Hacker News new | past | comments | ask | show | jobs | submit login
Sucking carbon dioxide from air is cheaper than scientists thought (nature.com)
531 points by kjeetgill on June 7, 2018 | hide | past | favorite | 281 comments

Remember that, a priori, you should be far more skeptical of studies with this sort of result than, say, studies showing that neocortinoids don't harm bees or that the latest blockbuster pharmaceutical has no side effects. The sheer mass of money in position to lobby for the "fossil fuel use is fine!" position dwarfs that of all other financially-fraught research questions put together.

To wit; the company behind the paper in question, Carbon Engineering, is noted by Wikipedia as having "oil sands financier N. Murray Edwards" as one of it's principal backers. And the article's "outside expert's opinion" quote comes from Stephen Pacal, co-director of the Carbon Mitigation Initiative at Princeton- which has an "extended partnership with BP" worth a great deal of money [1]. The financial conflicts behind this research are staggering.

[1] https://www.princeton.edu/news/2010/11/18/carbon-mitigation-...

this is kind of interesting as there's some reverse/upside down ideas that come out of it:

1. the big oil companies and the massive political machine that supports them drops the whole "global warming isn't real" line, no more snowballs being taken in to congress and all that. Because now they can just say they'll suck it out of the air and they can continue to think they can keep burning all the coal and oil they want (which of course they should not). Once everyone is on the same page that global warming is real, they can't go back on that. If the approach here proves to be insufficient (which it probably is), a lot of political points have been scored in any case.

2. the machinery to suck out the CO2 is another big "green" industry, like solar or wind, but doesn't compete with oil/coal! it's meant to mitigate the damage they do. So as you've noted, way more money and attention might end up going here, increasing the chance of its viability.

3. No matter what happens with the rate of burning oil/coal, we need this anyway. There's consensus that we're pretty much over the point of no return with warming due to all the ice that has melted, and if the permafrost goes that might be catastrophic.

The worry is that the discussion will create a false sense of future security, undermining current mitigation efforts. Or worse; that hope for future technological options can be politically weaponized to undermine more immediate actions. There are plenty of entrenched interests that have immense short-term incentives to do just that. Climate engineering will eventually help us mitigate some of the consequences. Some form is pretty much assumed as a given necessity even. But there are major mitigation efforts to be undertaken now. The earlier we mitigate the effects, the less extreme the interventions with climate engineering will need to be in the future.

Because no matter how much the price for direct air capture (DAC) falls in the future, it's still going to be massive. The submitted paper estimates a current cost of between $94 and $232 per ton. That's a big drop from a decade ago on a per ton basis, but it's still massive overall. At the low end you're looking at a minimum of ~$1.34 trillion annually if we were able to capture 100% of the 32.5 GtC of emissions accumulated in the atmosphere in 2017 alone. That's also completely ignoring the total ~230 GtC of the same since 1870 as well as emissions absorbed by the land and oceans (which has its own negative effects).

Nobody expects to remove all of it, or even all of what we'll continue to emit via DAC. Just keeping the expected increase to under the 2°C degree upper limit agreed to in the Paris Agreement is going to be challenging in itself even with cheaper, more efficient DAC methods. Actually reversing the temperature changes would be the "dream" for climate engineering. Something like that--which would involve every type of carbon dioxide removal methods along with atmospheric and space-based solar radiation management--would be a herculean project on a scale the human race has never before attempted. It'd make the Apollo program look like a five year old with a lemonade stand. And eventually, we'll have to figure out a way to make real progress on that front.

Basically, the hope that climate engineering will allow us to fix it later--or better yet, the dream that we can reverse it altogether--is both appealing and potentially dangerous. Why sacrifice today when we'll figure it out tomorrow? Just look at US infrastructure spending for an example of that kind of thinking.

"At the low end you're looking at a minimum of ~$1.34 trillion annually if we were able to capture 100% of the 32.5 GtC of emissions accumulated in the atmosphere in 2017 alone."

Just $1.34 trillion for the recycling of carbon of an entire year like 2017 is crazy cheap. Once installed, the machines can recycle every year for much less money. One has to wonder why it has not been done alreday.

Compare with:

Annual global fossil fuel subsidies amounting to $5.3 trillion in 2015 (6.5% of global GDP): https://www.sciencedirect.com/science/article/pii/S0305750X1...

Dr. Mark Skidmore – $21 Trillion Missing from US Federal Budget: https://www.youtube.com/watch?v=7CwpjIwwI9o

> One has to wonder why it has not been done alreday.

Psychology, I think. We’re not, as a species, good with numbers like that. Brexit was fought over a much smaller sum, both gross and as a percentage of the economy.

IMO lack of knowledge, lack of technology (e.g. affordable electric cars), bad contracts, conservative politicians (and voters) and corrupt politicians.

Corrupt in the sense of personal profit (including lucrative talks and positions in companies and donations by companies) and profit for established national companies.

I think there is an easy way kill this DAC concept. Have a tax on fossil fuels that in 10 years time ramps up to the cost of capturing CO2. The government will use this tax to buy services of companies that do this. Big companies can also capture CO2 themselves and pay less tax (or get a refund) if they can prove they did so.

This way, you can bet on DAC becoming cheap, or you can invest in renewables.

> easy way ... tax on fossil fuels

I'm not sure those two phrases belong in the same paragraph, for the same exact reasons stated by the gp.

The Paris Climate models (1.5 degrees and 2 degrees) assumes that we are going have to remove a lot of carbon. This is not an either or - we need to both move to a carbon-free economy and remove carbon

> we need to both move to a carbon-free economy and remove carbon

We need to move to a net negative carbon economy (not carbon free, net negative), or find ways to reduce input heat (reflecting sunlight basically).

Not sure how accurate but napkin maths and quick google suggest barrel of oil produces 118 kg of co2. So about 9 barrels to produce a ton. Barrel is $67. So cost of capture might add 15% to 38% to cost of oil.

This is not correct. A barrel of oil is 118kg of pure carbon but when burning this translate to roughly 450kg of CO2 (because carbon combines with heavier oxygen to form CO2)

This is without taking into account the CO2 that is emitted to extract the oil from the ground.

Yes, the simple "rule of thumb" is "the resulting CO2 is 3 times heavier than the gasoline burned." Because chemistry. H weights "almost nothing" (in the engineering approximation sense, to the first order of magnitude) in hydrocarbons, and the weight of a single CO2 molecule (made of two oxygen atoms, one carbon atom) is roughly 3 times the weight of C atom alone (again as a good enough simple approximation, it's a little more, but C alone is a little lighter than O, so all together with the starting H, everything comes to 3).


For those who like more exact calculation: one molecule of C8H18 (octane) weights approx 8 * 12+18=114 masses of H, only that one molecule will produce when burnt 8 CO2 molecules, which weight 8 * 12+2 * 8 * 16=352, and 352/114 ~ 2.98 ~ 3

the ~$100 per ton of CO2 is only to capture CO2 to the form of K2CO3, the energy cost to convert this to fuel will be much more!

I believe what the poster was implying is that in a future scheme, the cost of carbon capture would be directly added to the cost of the fuel. This is in line with other extraction industries, e.g. logging, where the loggers must plant replacement trees. The cost of that replacement is incorporated into that of the lumber, wood pulp, etc.

In the future (where all fuel is manufactured by energy from renewables), the price of carbon fuel would simply be the price of manufacture: capturing CO2 and energizing it into fuel. Or are we celebratinng the fact that some people learned about objective energetic cost today? Capturing CO2 has never been hard, and to make the analogy with the loggers planting trees more complete, the price component due to capture would be almost nothing compared to the price component of turning CO2 into fuel which would make up the majority of the price of this future fuel.

And how do you get enough substrates, plus how expensive and energy intensive they are?

I looked up how much volume a tonne of CO2 takes at average temp/pressure.

A sphere with a diameter of 10M.

That's an insane volume when you think about it.

> The worry is that the discussion will create a false sense of future security,

A false sense of future security already exists, but on the opposite side! I'm sick of hearing people complaining about pollution and how we should switch to greener energy, without ever specifying which such magic green source of energy we may use!

I hear a lot about electric cars, but it's not clear to me what is an acceptable way to refill those batteries: burning oil in big thermal stations instead of private engines? Nuclear? New dams for hydroelectric?

When will people swallow the fact that our current lifestyle depends on the availability of cheap energy and that such energy has to be taken somewhere? Please, let's stop saying stupidly just "no". Let's rather look for alternatives and we'll all be happier!

> the big oil companies and the massive political machine that supports them drops the whole "global warming isn't real" line

They dropped that a few years ago




Although... https://www.citgo.com/NewsViews/CITGOViews/GlobalWarming.jsp

From the Shell link:

Gas can help with all three of the UK’s energy objectives – providing affordable, secure and low carbon energy.

Gas is none of those things. It’s not cheap, it’s going to run out, and it isn’t low carbon.

This is somewhat true, though obviously misleading.

Since natural gas's energy efficiency is much higher than that of coal or oil, the amount of carbon dioxide released is the same for a greater amount of energy. Furthermore, it requires less carbon input to retrieve the natural gas.

Also, in order to use solar or especially wind, you need a form of electricity generation which can ramp up quickly when the wind dies. Until we get large-scale battery storage, that means natural gas turbines.

It is cheap - see the huge fall in gas prices since the introduction of fracking. The US has gone from being a net importer of natural gas to an exporter, such is the increase in supply.

"Secure" doesn't mean "is never going to run out", but rather that we don't have to rely on other countries from it. The UK can meet some of its natural gas needs with local fracking, reducing the need to import gas.

(And other commenters have addressed the low carbon thing)

All true. But note that GP didn't say that they've stopped spinning started speaking the complete truth about fossil fuels--only that they have stopped denying its link to global warming.

Some gas is renewable, though, so definitely low carbon. And over here it's even fairly cheap (for vehicles, considerably cheaper than gasoline).

You can replace the reason any corporation does things with $profit and it will almost always make sense.

I don't know about big oil, but the machine continues. The WSJ published this editorial in the last week:

Climate Change Has Run Its Course


And they charge you money to read it, how nice of them! I hope they spend it on solar panels.

If you google for the title and click through, the WSJ will let you read the article.

But frankly, it's not worth it.

TLDR: Climate change is past its peak as a cause because it's being co-mingled with other social justice concerns and because of concern fatigue.

> They dropped that a few years ago

They say they dropped it, or they stopped funding conservative think tanks and pols?

Citgo is de facto an arm of the Venezuelan government, so of course it stands in favor of carbon credit schemes whose net effect is funneling money yo Venezuela.

> Once everyone is on the same page that global warming is real, they can't go back on that

I'm not sure that's true, at least in the US. The extent to which "post-truth" has become a meaningful phrase since 2016 is disheartening.

And of course, the cynical would say that it doesn't matter. If carbon-pollution lobbyists can go from "it isn't real" to "it isn't a problem" then they will have achieved their goal. This is true whether or not these technologies are technically or economically feasible.

Getting excited about an imagined giant CO2-fixing industry is the broken windows fallacy on a planetary scale: https://en.wikipedia.org/wiki/Parable_of_the_broken_window

> way more money and attention might end up going here, increasing the chance of its viability.

This has no chance of ever being viable. Reducing energy usage is way more efficient than 'mitigating' carbon. And if you wanted to mitigate carbon, it costs $0.03 cents per ton just to reduce deforestation, whereas this costs $94 per ton.

Here's a dollar. Who can I pay it to so that 30 tons of forest get saved ?

It doesn't matter about the estimated costs of something (feel free to share sources also) if people aren't going to actually do the thing. Even the most extreme and fully impossible reduction of carbon emissions, like banning all cars on Earth (which would also have immense social and economic costs in itself) will not reverse the problem now. All strategies must be employed at once.

There are non profits that do things like buy land for conservation. I don't know which ones are efficient and effective so I won't try to name a specific one.

This approach is also risky. We don't know what climate effects might fall out of very fast, very localized changes in the composition of the atmosphere. What's it going to do to the climate if we suck a bunch of carbon dioxide out of the atmosphere in one localized place? Could it change air movement patterns? Cause extreme weather events as the atmosphere moves around to remix itself?

I don't know if any modeling has been done on this (or if modeling it is even possible), but I'd be very worried about unintended side effects with the large scale, intensive application of this sort of technology.


'As you can see, in either scenario, global emissions must peak and begin declining immediately. For a medium chance to avoid 1.5 degrees, the world has to zero out net carbon emissions by 2050 or so — for a good chance of avoiding 2 degrees, by around 2065.

After that, emissions have to go negative. Humanity has to start burying a lot more carbon than it throws up into the atmosphere. There are several ways to sequester greenhouse gases, from reforestation to soil enrichment to cow backpacks, but the backbone of the envisioned negative emissions is BECCS, or bioenergy with carbon capture and sequestration.

BECCS — raising, harvesting, and burning biomass for energy, while capturing and burying the carbon emissions — is unproven at scale. Thus far, most demonstration plants of any size attaching CCS to fossil fuel facilities have been over-budget disasters. What if we can’t rely on it? What if it never pans out?

"If we want to avoid depending on unproven technology becoming available," the authors say, "emissions would need to be reduced even more rapidly."'

CEO of Canada's largest oil company: "Suncor CEO slams climate change deniers, politicians who cater to them"


Choice quotes:

"It is a matter of profound disappointment to me that science and economics have taken on some strange political ownership"

"Climate change is science. Hardcore science."

"It makes sense to consume things sensibly. Common sense is not a big part of the conversation that normally goes on on this thing."

I think the strategy is changing from denial...

Is anyone actually debating if climate change is happening? The debate is on the degree of human influence.

During the last ice age there is evidence that suggests the Earth's temperature rose 10-15 degrees in less than 10 years. In fact, during the last 110k years represented in the Greenland Ice Sheet Project the climate shifted dramatically multiple times over periods of a few years to maybe a couple of dozen years. During the last 110k years the most stable has been the last 11k years, which is kind of just dumb good luck for us living today.

Current anthropomorphic climate change models suggest we might see 2-3 degree changes in 100 years. I believe the science is likely accurate here. I support moving towards renewables and just about anything else generally supported by the climate change crowd. However, I think the panic button has been pushed a little too hard on this issue. I think things like overfishing the ocean and even plastics in the ocean are going to be bigger problems in the short run than human caused climate change.

Generally speaking this kind of nuance isn't allowed. The kind of response that says "If water rises a few feet, move a few feet inland, you've got a century of notice. If you have to farm over there instead of over here, then farm over there instead." is sacrilegious. To many, I would be considered a "climate denier."

The economic impact on the United States alone will be in the trillions. Relocating all of Manhattan, Toronto, London, Singapore, and other coastal economic centers is non-trivial, but would hopefully be gradual enough to be viable. It would be fantastic if we can avoid this loss of wealth by making a meaningful reduction in the rate of global warming.

Other nations are already experiencing famine due to permanent desertification. This has already exacerbated political and military conditions; drought is a major factor in the Syrian and other war zones.

To compare this to the range of human history is not meaningful. "They had it worse" isn't helpful for now. What matters is our response to the conditions that we are expected to experience.

Around the 120,000 BCE time, there was a "great filter" event that caused the mass death of most of humanity, causing a massive reduction in human genetic diversity. Yes, we may have it "easier," but today's problems are still real and must be dealt with.

I think it's useful to frame the climate change process solely in terms of human impact, and specifically economic, political, and security terms to governments.

I wouldn't consider you a denier, and it's important to share your perspective. I hope you consider mine.

The cost of the Iraq war is in the trillions. A cynic could argue that that war happened to secure burnable fossil fuels.

It isn't obvious that the cost being in the trillions is cause to blanch - at the scale we are talking, the cost of mitigating with more expensive energy is also likely to be in the trillions.

You might benefit from being more specific about how many trillions.

I think this is even more alarming:


Of course they are, including nearly half of US politicians. There are people in this thread that are unsure if humans are even increasing CO2 levels.

This is a political debate, not a scientific debate. And the political debates mean stating the most extreme position that's within the realm of plausibility. Or having others say even more extreme things to move the window of plausibility.

It's hard making some people understand that such debates go beyond the scope of science (or that there's anything beyond the score of science for that matter) :/

Even better: there are politicians(0) and 'leaders'(1) in the US who still outright deny that it (climate change) is a thing. One of them is even head of the EPA. lol.

0. https://www.washingtonpost.com/news/energy-environment/wp/20...

1. https://www.factcheck.org/2016/11/trump-on-climate-change/

Maybe I'm missing something, but can you point to a line in [1] where Trump outright denies climate change is a thing? I see a lot of qualified statements like "climate change is a 'very complex subject'" and "Trump said there is 'some connectivity.'"

Others have beat me to it, but gosh, you really don't have to try very hard at all to find examples of him denying that it's a thing.

Now. 5 years ago it was if it is even happening

One can reasonably question if climate changes can be reasonably measured over a 150 year time frame. At a geological scale climate change has been ongoing for about 4 and a half billion years. Saying that the latest .3333x10^(-6)% of that data stream is sufficient to deduce a new trend is pretty amazing if true.

On the other hand processes like glaciation and desertification can happen with alarming rapidity. Supposedly the former can occur in less than a year http://www.dailymail.co.uk/sciencetech/article-1227990/Ice-A.... Those are two kinds of climate change that I consider cause for concern. The dust bowl was a big deal. And then there are things like super volcano eruptions.

Having more historical data to draw on makes us more confident that the null hypothesis is invalid, not less. If the question is reasonable, then the answer is an immediate, equally reasonable: yes; we've done the measurements; the data is there; the trends are clear.

An alternative motive, which makes slightly more sense to me, is that oil and gas companies have a vested interest in developing this kind of technology because that's the only way their business will survive in the long run. Fooling people (including the editors of peer-reviewed scientific journals) with spurious research into CO2 recapture methods seems about as hard, and still not as effective, as actually developing those methods.

Plus, if they successfully develop the technology, they get to run two complementary businesses instead of just one, kind of like owning a bar with a pay toilet.

I think that the much cheaper solution is neither to develop the technology nor fool people with fake research, but fund real research into areas where the economics probably won't work. (Which could be the whole field.) As we've seen with Theranos, and with plenty of smaller companies [1], it's easy enough to spend years taking investor money for things people want to exist but are probably or definitely impossible. That would get carbon polluters many years of delay. For corporate execs, that's plenty of time. And hey, a miracle might happen.

That said, fooling people is a well-established business of its own. It started with the tobacco companies, but it sure hasn't ended there. [2] So they might be sticking with the tried and true playbook here.

[1] E.g., this excellent blog on wireless charging companies: https://liesandstartuppr.blogspot.com/

[2] https://www.amazon.com/Doubt-Their-Product-Industrys-Threate...

Meh. Anyone with serious expertise in an area will have "ties" to the relevant industry.

If people with such ties are untrustworthy, that means no experts can be trusted, and all you're left with is the uninformed and various angry activists.

I'll take my chances with well informed experts who are possibly not perfectly impartial.

When corporate grants are bringing research groups into existence more or less from scratch, it's fair to call it more than "ties." At the very least, this is far beyond the norm in fields I keep track of- for instance, pharmaceutical companies helping fund academic biomedical research happens, certainly, but only in limited cases and generally it's considered a significant asterisk next to whatever the study finds. When those same companies are carrying out their own research (say, clinical trials for a new drug) they typically do so under external supervision, with rigorous reporting standards.

For that matter, the choice isn't between oil-industry experts and complete novices. Carbon capture is chemistry; there are plenty of chemical engineers with independently-funded academic positions, or involved in non-oil-industry funded companies. If some of them published a review of the plausibility of carbon capture, I'd listen to it.

But there is no advantage here to produce FUD. In fact it acknowledges the primary problems of fossil fuels, not deny them. They are not seeking FDA approval on a drug, or trying to show that CO2 makes us smarter and healthier. I won't use more gas now because of this article. However, if they can do it (and they have for several years in a test), then we can slow the rate of new carbon, while the growth of solar continues to grow, I think it is a potential win for us, and for a company able to do it.

You will absolutely use more gas because of this article. Just the headline out there will have an effect (since people tend to remember mostly the headlines). When your local enviro-hippie comes and starts asking you to fly less, drive less, buy local, save energy, etc... -- you'll have just slightly less incentive to do that. "What's the big deal", you'll say. "We can just suck the CO2 out of the air."

I think this is exactly the effect that fossil fuel companies hope the FUD will produce.

It ignores the energy cost to turn the damn CO2 into fuel. If we had a cost effective way to BOTH capture CO2 AND turn it into fuel, then we wouldn't be drilling for fuel..

It ignores the atmospheric CO2 that is no longer abosrbed by the greenhouse plants by feeding them this CO2: in this sense its $100 dollar per tonne CO2 more expensive than letting the greenhouse plants extract it themselves!

It's just a good news show, now nature.com is doing it too!

Meh. You’ll only take your chances with someone who absolutely has conflicts of interest is what you’re really saying.

No, what they're saying is that conflicts of interest are so common and mundane that they don't have much signal on their own.

I hear you, and in terms of the merits of this particular study I'm sure your skepticism is well-grounded; I share it. But, it's also worth considering the perspective of the "Big Oil" executives. Thought experiment: imagine you're such an exec, and you recognize that the future of your company (in fact, your whole industry), depends on evolving beyond oil, to become an _energy_ company, embracing (and innovating in, and profiting from) renewable sources. What do you do? How do you start? I am NOT repeat NOT an apologist for the selfish idiot criminals (insert unprintables here) who effectively destroy the planet for personal gain. And yes the fossil fuel industry as a whole has a horrible and well-deserved reputation. But some of these entities are going to adapt and change, and for better or worse they're going to play a role in how our species relates to the planet. So I think it's really important to remain skeptical, but without ruling out, out of hand, the possibility that ties to the energy industry are not an automatic disqualifier for real science and progress.

It's a question of scale, the oil industry is vast. Exxon has ~1/4 of a trillion dollars per year in revenue while profits swing they tend to be very good over time.

Renewables on the other hand are fractured. Do they go for Wind, Solar, Batteries, Bio fuels, or what? It's not that hard to keep Exxon alive through this transition, but you also need to keep it huge and profitable which is very tricky.

IMO, they might be better off going into chemistry or engineering because being an energy company sounds fine there is little connection between renewables and oil. But again how do you keep that kind of scale?

This is indeed part of Exxon's publicly-stated strategy; they recognize that the demand for oil will peak once renewables, distribution, and storage technology are cheaper than the cost of extraction. There are already several solar power plants that were built because the unit economics made sense in those rare, outlier situations. This will become more widespread.

> The sheer mass of money in position to lobby for the "fossil fuel use is fine!" position dwarfs that of all other financially-fraught research questions put together.

Not only that but a very large number of people want to believe results like this are true. People are really scared to downgrade their lives and will resist at any cost. Clinging to delusional beliefs is one of the oldest tricks in the book.

Noting conflicts of interests makes sense, but the point of the article may still stand. Why is there no market force for extracting CO2? Do any emissions trading systems include folks who capture emissions and improve the "supply side" of the equation?

The US gives tax credits of $50/ton for underground storage and $30/ton for usage of the CO2.

So, about 5 cents per gallon of gas?

That is a complete joke.

Coal prices vary, but can be as low as $50/ton. If you set the price for carbon burial much higher than that, it enables a business model you might not want to encourage.

You mean burning coal and capturing carbon back to profit from the price spread?

I think they mean digging up coal and burying it in the ground again. Carbon captured, mission accomplished!

The current spot price for a short ton of coal is $40 [1], if it stays this low for a while, and the subsidy is in fact above that price, then watch out for some "business model innovation" in this space.

[1] http://www.infomine.com/investment/metal-prices/coal/5-year/

Its one of the higher non-gas tax incentive schemes in the world actually. Of course that's not saying much.

Not really. The influence:price ratio of academia is very high -- they can be bought very cheaply. It doesn't really take much to fund a study compared to the earnings of a big corporation. Tesla or similar could easily fund anti-fossil fuel studies and categorize them just as miscellaneous marketing expenses.

Are there other experts without conflicts of interest who have offered critical assessments of this research?

I agree that lay readers should be skeptical of experts with a vested interest in an outcome. But that doesn't mean we should be unduly pessimistic about research that has only positive evaluations (and is in Nature) as of yet — even if all of the experts who've weighed in have financial or other relationships on one side of the issue.

Really? I view this research as opening the way for laws mandating oil/gasoline producers reach carbon neutrality by funding/implementing mass carbon extraction as part of the cost of drilling.

Sure, they'll still be doing massive ecological harm with oil spills, disruptive drilling, fracking-related earthquakes/water reservoir contamination, and so on, but at least we won't bake ourselves to death, there's that ¯\_(ツ)_/¯

I would expect the opposite. If carbon sequestration is cheap, then it's not a big deal to demand that businesses purchase offsets to be carbon neutral.

But, I'm still skeptical because these sorts of breakthroughs are always overhyped. If it's real, the proof is in the pudding.

> The sheer mass of money in position to lobby for the "fossil fuel use is fine!"...

Please, let me play the role of the devil's advocate for a moment: fossil fuel use is fine! It MUST be fine!

Fossil fuel gives people cheap energy that used to come from muscles (human and animal) and, in particular, comfortable ways to move around, where you want, when you want.

People switched to fossil fuel as soon as possible because life got immediately enormously more joyful.

Global warming is two more Celsius degrees for average atmosphere temperature. Give me two degrees less each day and I'll give you back my car... just to ask it back the following day, and maybe I'll propose you to give a couple more degrees each day in exchange for no more whining about good old days' cars (nowadays labelled as "polluting" cars).

> The sheer mass of money in position to lobby for the "fossil fuel use is fine!"

I wish them all the best. At the end of the day Shell has come forward and indicated that renewable energy is best, despite their namesake. I'd own an EV if I could, but I can't: the next best is a hybrid. The two times I fill up a month I actively seek out Shell because of their stance. There are PR implications.

Imagine a world where fossil fuels are fine (not fossil really, but carbon). I have great and frankly revolutionary ideas surrounding easy and fast EV refills, but they are simply horrific in the face of turning electricity from renewables and atmospheric carbon into fuel.

My physics Spidey senses are tingling and this sounds too good to be true, but if it isn't: god speed.

Doesn't change anything. I still would take the method that produces no air pollutants as my number one choice. I also care about localised pollution from cars etc and not only climate change.

Doesn’t the anti-fossil fuel crowd have similar incentives?

Shouldn’t all studies be held with skepticism?

If the results were the opposite, people with ideological intent would be trumpeting this study as further confirmation of their own bias.

Basically it sounds like you are saying, “be skeptical of anything that goes against my deeply held beliefs because my cause is just while the other side is evil.”

Selective skepticism is a bad way to do science. Scientists should be skeptical of everything that doesn’t have repeatable experimental evidence.

Am I understanding your point correctly?

I feel the controversy comes from the fact that one side has a large fund of money and is biased towards keeping things the way it is, whilst the other has significantly less funding and does not earn any money, or likely even significant benefits from the other side (mostly the young and poor will be affected, neither of which hold as much political clout).

All studies should be held with skepticism, but (assuming skepticism is a "resource" that can be exhausted), we should likely focus more of our skepticism on studies that clearly benefit from the result of the topic being discussed.

I object to the idea of limiting new carbon production is keeping the same. It is more like a victory. Solar continues to grow, and fossil fuel companies are being forced to come up with ways to make themselves carbon neutral. Sounds like a win.

Technically a good quarter with positive cash flows is profitable - even if the firm has been making losses for years.

The oil giants have helped suppress research, pervert justice and many other things to prevent this day.

It is here because the inevitability of reality makes it so.

I’m glad we are here, but we needed this 30 years ago.

No. The anti-fossil-fuel movement, in general, doesn’t have tens of billions of dollars at their disposal. Deeply held beliefs may certainly influence scientific research, and that should be guarded against, but by itself it doesn’t let you buy scientists wholesale.

The diehard AGW "skeptic" needs just two simple maneuvers to counter any high-profile messenger warning about climate risks:

1) If the messenger has not invested their own money into efforts to reduce emissions, say "they won't put their money where their mouth is."

2) If the messenger has invested their own money into efforts to reduce emissions, say "they're just scaring people about climate to profit from their investments."

It's funny how people are still having these conversations on the eve of the bicentenary of climate science https://en.wikipedia.org/wiki/Joseph_Fourier

Doing a little math...

Considering 1100 Gtons in the atmosphere and $200 per ton would be roughly $220 trillions.

The current world's GDP is $78 trillions.

Even if the world invested $10 trillions every year it would still take 20 years to remove all the carbon emitted between 1850 and today.

Of course we would keep pumping about 37 Gtons per year (and growing).


This industrial approach to carbon dioxide removal is but one of several in our toolkit, and by no means the least expensive.

Project Drawdown ranks every approach in terms of tonnage of CO2 and cost. http://www.drawdown.org/solutions-summary-by-rank

These approaches get amplified by a price on carbon. If you are interested in convincing your Member of Congress to price carbon, take a look at the most effective organization doing this work: http://www.citizensclimatelobby.org

Thank you for introducing me to Project Drawdown. How eminently practical and sensible these recommendations are. I love the data-driven approach.

I was surprised to find that, of all things, "Refrigerant Management" is the single thing that holds the greatest potential to reduce carbon emissions [1]. It makes a lot of sense, but it would definitely not be what I would have guessed.

[1] http://www.drawdown.org/solutions/materials/refrigerant-mana...

that #1 single thing only makes up 89.74 of the total 1050.99 at the bottomm of that column! or about 8.5%

Thank you for spreading the word about Drawdown and CCL!

They are probably the two easiest ways regular folks can learn about and get involved in climate policy (and I mean real impacts, not just clicktivism).

Please get involved – it takes no money and very little time!

Sure... educating specifically only the girls is #6 on the list.

Why would they have to bring feminism into that? I mean sure, it's a good thing to educate everyone. But why mix it?

How can I trust all the other points on the list now? What if they are also just pushing some other political agenda?

I can't. They just compromised the list's integrity by that.

Women's education and empowerment is negatively correlated with the number of children they bear.

Did you read that section to see why they think it'll help? It doesn't sound like politics to me.

Yes I did. Because educated people have fewer kids... Might be true, but what kind of reason is that even!?

Why not also establish a one-child policy in western countries? Or start actively killing sick people? /s

All the other reasons were basically how it makes lifes better for those women. Which is surely a good thing, but doesn't matter in that context.

I’ve been sending the same math to people who’ve been getting excited about this. It’s premature. Even just trying to remove our annual emission would take 7% of our global GDP.

This needs to come down in cost 20x to be a viable solution to our problem. And that’s just going by cost, not looking at the logistical aspects. For example the plant pictured captures 1 million tonnes annually. So we would require 37,000 of those giant plants to capture our annual emissions. We haven’t explored how much energy would be required to do that and where we would get it from. The plant shown uses gas, a polluting power source oddly, and a very cheap energy cost figure in its calculations. Presumably we’d want to use solar. And thus half the efficiency of that plant. So double the number required to 74 thousand.

Everyone getting excited that this is a solutions has gotten ahead of the science and logistics. We’re far from being there.

Nuclear seems like a better option than solar. Assuming capital cost is a major factor, you'd want the carbon removal plant to run all the time, not shut down at night. Constant load is perfect for nuclear.

Or to take it a step further, massively build up Nuclear to match daytime peak (give or take some renewables) and then use carbon sequestration as the load on the grid at night time instead of batteries (or other sorts of storage).

There are countless ways to store energy: hydrogen, artificial hydroeletric, batteries, etc. Solar energy is practically unlimited. Nuclear still requires fuel, and it's a very limited resource unless you start considering things like extracting fuel from the ocean where costs just skyrocket.

And it's likely that our global energy usage will skyrocket in the future for a variety of reasons. The first level is that many places are still undeveloped and have not yet hit their 'China' phase. But beyond that we can also just do some really cool sci-fi soundings things if we massively ramped up our energy production. Fossil fuels, and fuels in general, were never really fit for these sort of ideas - but solar certainly is.

This [1] article goes into detail on the remaining nuclear material. Keep in mind that this is at current consumption rates. Energy usage rates are going to increase in the future, and right now only 4% of global energy production is nuclear. In other words, you can shave orders of magnitudes off the numbers they give in that article to give a ballpark for how long nuclear would last. It's just not a great fit for the longterm future.

[1] - https://www.scientificamerican.com/article/how-long-will-glo...

Scientific American is flat out wrong, compare[1]. (Someone who states that "a breeder creates more fuel than it consumes" has to be wrong about many things.) Common rocks contain about 13ppm uranium and thorium, which gives them a 50x higher energy density than coal[2]. We will never run out of rocks. As a bonus, if we actually "burn the rocks", we end up with a lot of sand to be spread on fields, which counters soil erosion, serves as fertilizer, and captures CO2 through accelerated weathering. In other words, solar power uses land, nuclear power restores land.

[1] - http://www.nuclearfaq.ca/cnf_sectionG.htm#uranium_supply

[2] - http://energyfromthorium.com/cubic-meter/

It's a misleading, but technically accurate marketing point for breeders. More specifically it's fissile material, which is converted from larger amounts of fertile material used in the reactor. There's no violation of conservation principles, just some fast talk. Read your own links - as at least the first mentions this.

The second link is junk. The average distribution of elements in the Earth's crust does not mean each every and every chunk of earth contains exactly that distribution. And while many types of rocks do contain trace amounts of uranium, it's nowhere near 13 ppm. Though so far as I can see even that site didn't state that.

> It's a misleading, but technically accurate marketing point for breeders

That's the point, it's not technically accurate. A breeder makes more fissile material than it consumes. Fissile material is the fuel in light water reactors, but breeders use a different, more abundant fuel. I know that, you know that, and we both know that we both know that. But inaccuracies like this lead to the likes of Helen Caldicott dismissing the whole technology with a sneer such as "a breeder that magically makes more fuel than it consumes".

> trace amounts of uranium, it's nowhere near 13 ppm

It's about 13ppm uranium and thorium, in fact about 10ppm thorium and 2-4ppm uranium. And while energyfromthorium doesn't state these numbers explicitly, it clearly uses them in the energy density calculations.

> does not mean each every and every chunk of earth contains exactly that distribution

So "burning the rocks" will never work, because there are a few rocks that don't burn? It works even better, because some rocks burn better, e.g. Conway Granites at 56ppm thorium.

I'd expect we'd need either fast reactors or thorium reactors to cover that much usage. Either would be about 100x more fuel-efficient. There are two fast reactors operating commercially in Russia.

Extracting uranium from the oceans is about 5x more expensive than mining it. Since fuel is a small component of nuclear cost, that's not a big deal; we don't do it right now because mining covers our needs. With fast reactors, it wouldn't be a problem at all, and would cover our needs for many millions of years, even at much higher consumption rates.

Storage adds quite a bit of cost to solar (other than hydro, which is geographically limited). If we get storage technology that makes storage+solar cheaper than nuclear, then sure, that might be better.

However, we're already nearing a planetary limit on land usage, after which we seriously impact biodiversity. The vast solar arrays this would require wouldn't exactly help.

Fuel, at least according to Wiki [1], runs about 28% the cost of a nuclear plant's operating expenses. And our current nuclear tech was chosen largely because it was cheap. You're also looking at much greater expenses in running breeder plants. Those are already pretty substantial costs. And now on top of the cost extracting/refining/enriching fuel from saltwater would cost, you also have to keep basic economics in mind as well. Right now there's little demand for nuclear material, and so this is reflect in its cost. However, should this change you'd expect to see the cost change in turn, and likely quite sharply. That's a lot of stuff piling up pretty fast!

I'm not sure where you're getting he millions of years for breeders. The article mentions the value I've seen pretty much everywhere which saltwater extraction could theoretically provide enough material for about 60k years of nuclear operation. And breeders could ideally reduce consumption to a bit less than 1% of current usage. So that'd be 6 million years, but that's at current consumption rates. If we replaced our energy with nuclear that'd be a 25 fold increase in usage so we're down to 240k years at current rates. And that's in the scenario where we're extracting all the material we can from ocean water, using every single resource we have on the planet, and doing it all with perfectly functioning breeder reactors.

Just seems we should be targeting something that isn't a numbers game, though granted you can probably make some argument that cobalt will be a limiter on solar but solar also comes with many other perks - decentralization, minimal danger from failure, much cheaper, practically infinite energy availability, and so on. The only issue is storing energy, but this can be done affordably in numerous ways even with present day tech - and decentralization can also remove lots of the burden here.

[1] - https://en.wikipedia.org/wiki/Economics_of_nuclear_power_pla...

So only, say 100K years before we have to figure out fusion or something? I'm thinking we could live with that.

However, uranium in seawater is actually in an equilibrium, so the more we extract, the more gets dissolved from rocks. Effectively it's a renewable resource:



Whether breeders would be more expensive depends on their design. One that looks quite economical, according to independent engineers who evaluated it, is Moltex:


20 years is an incredibly quick timespan in which to do this. If we can become carbon neutral by 2040 and carbon negative after, we can stave off many of the worst parts of climate change.

I'm with you. I have to believe a joint country climate accord where member nations pledge to suck X gigatonnes of carbon from the atmosphere (or finance those that do) is a much easier political sell than 1) taxing fossil fuel companies/cartels or 2) enforcing emissions restrictions on various industries.

Cleaning up 150 years of emissions in 20 or 40 or even 60 years seems like a miracle on par with the moon landing or eradicating smallpox.

I love your real-world examples of "miracles"!

In front of me right now I have the June issue of the IEEE Spectrum special report, titled "Blueprints for a Miracle: 10 Technologies for a More Livable Planet". Its highlights include carbon-eating fuel cells; turbines driven by super-critical CO2 (nearly "free" carbon capture, courtesy the Allam cycle); a plant in Iceland producing methanol fuel from renewable (geothermal) energy and waste CO2; a pure-electric airplane; plant-based and in-vitro meats; and a sodium-cooled travelling-wave nuclear reactor with decent performance.... It seems to me like we're coming to the fight awfully late, but we may also have more weapons than we'd realized.

Just stopping things from getting worse would be an achievement on those scales.

An economic loss of $10 trillions per year during 20 years would be catastrophic for the economy. It's simply not sustainable economically.

Also, let's not forget that our emissions are still significant (and growing) and that feedbacks will keep on warming the planet regardless of what we do.

We're not talking about an economic loss, we are talking about a potential subsidy to a sector of the economy to build massive numbers of carbon capture facilities. I'd prefer a $1 trillion carbon-mitigation subsidy over a $1 trillion tax cut to be sure...

This debate feels a bit like people talking about how much money is 'wasted' on a Mars rover, ignoring the difference between "the value of materials shot into space" and "the total cost of building something, including salaries and capital expenditures that aren't destroyed".

The cost of doing something is not the same as an economic loss from doing it.

Would doing so in such a short timespan have a big effect on the weather during the transition?

Maybe the first goal could just be removing the current year's production? That would still be a vast improvement over every other proposed solution.

By his numbers that's still ~ $7.4 trillion, or about 10% of the world's GDP. And it doesn't include storing the captured CO2 anywhere permanent.

I think it's a lot more practical to reduce our emissions to close to zero, hard as that is.

Anything we do is going to be expensive. "Stopping all use of fossil fuels" like you suggest would also be very expensive, even if we ignore obvious costs like disposing of all the corpses created by such an endeavor.

Presumably, Zeno's Paradox will be hard at work. We don't have to remove it all in one go. We just have to remove it faster and faster and faster, as we get closer to the limit (whatever that limit is).

This isn't my field, but so many human endeavors go like that. Just buy a little time so we can figure out how to do better, which then buys time to figure out how to do even better.

By many accounts we have already passed the limit.

If we're totally screwed then it doesn't matter what we do; so frankly it isn't really worth thinking about. Better to assume we can save ourselves and try, than assume we are doomed and give up.

There are many tons of emissions that can be avoided for far less that $200/ton. These are the things like stopping the burning of fossil fuels, increasing energy efficiency, planting trees, capturing from industrial point sources, etc. DAC is the high cost alternative, that means it will be used last as a strategy for dealing with CO2 emissions.

Seeing as that the entire world economy for the last century, responsible for the greatest reduction in poverty in the history of the world, is driven heavily by fossil fuels, it does not seem that unreasonable.

You don't need to capture anywhere near the total amount emitted into in the atmosphere. Just enough to offset warming.

That "just enough" is probably half of what is presently in the atmosphere. The oceans have absorbed huge amounts of what we've emitted, and would disgorge it accordingly. The CO2 level in 1900 was about 300 ppm; now its 400. To make a substantial reversal in climate change by only removing CO2 from the atmosphere, we'd have to make a massive stride by 2050.

The oceans may also end up being a higher priority at least at first because there is already evidence that acidification caused by absorption of excess atmospheric carbon us causing ocean ecosystems to break down while disruption on land is still relatively minor.

I'm not sure you can target oceanic CO2 over CO2 in the atmosphere. Ocean acidification is an equilibrium process driven by the partial pressure of CO2 in the atmosphere increasing.

If you start reversing acidification, the ocean is just going to start pulling in more CO2 from the atmosphere.

Sounds like you should "just" target whichever one is easier (cheaper) to pull CO2 out of, then.

In most cases it is easier and more practical to accelerate reactions in liquid media as opposed to gases. This is chemistry not magic.

There are a couple of problems here.

1) Nobody really knows how much is that. 350ppm? 300ppm? 250ppm?

2) Don't forget about feedbacks which have already been triggered and will keep adding warming regardless of what humans do.

Your math is not wrong but your assumptions are. We only need to remove enough to produce fuel so that we can stop dumping c02 in the atmosphere by consuming oil and replace that with what we produce from co2. Once we do that, nature will do the rest. Slowly of course but it will trend the right way. So, there is no need whatsoever to actively remove that many tons of CO2.

My thing is that we should be charging/taxing the companies producing these sorts of emissions. But of course capitalism is about socializing the costs (fixing these emissions) and privatizing the profits.

On top of the fact that this probably doesn’t scale up to geo-engineering scales linearly even if you assume the article is correct in the costs it gives.

Reminder: If CO2 levels fall below 150 ppm there will be a mass extinction of land-based plants.

It is a grave mistake to believe that CO2 as such is bad and must be removed from the atmosphere. It is an essential fertilizer for both phytoplankton and land-based plants (at current levels these plants are in effect starved for CO2, because they evolved during geological time periods with much higher CO2 levels).

That's like saying that not eating for a month will kill you, in response to an article about the obesity epidemic.

I hope this is not your usual standard of thinking or argument.

At what CO2 level in the atmosphere would land-based vegetation go extinct? should one take this into account when designing or advocating massive mechanisms to remove CO2 from the atmosphere? once you've admitted that some CO2 level is good for the planet, why and how do you determine an ideal/target level?

1100 GTons is what humans have added on top of the natural CO2. Nobody is saying we should remove all CO2.

Your asserted number (1,100 GtC) seems to be a wild exaggeration: "In the period 1751 to 1900, about 12 GtC were released as CO2 to the atmosphere from burning of fossil fuels, whereas from 1901 to 2013 the figure was about 380 GtC." [1]

"From 1870 to 2014, cumulative carbon emissions totaled about 545 GtC. Emissions were partitioned among the atmosphere (approx. 230 GtC or 42%), ocean (approx. 155 GtC or 28%) and the land (approx. 160 GtC or 29%)." [2] (And 230 GtC is 843 GtCO2, so that doesn't match either.)

Your asserted number appears closer to an estimate of total GtC in the atmosphere, not merely the modern addition via human CO2 emissions. Where did that 1,100 number come from?

[1] https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_at...

[2] https://www.co2.earth/global-co2-emissions

I tracked down one scientific paper that mentions "1,100 Gt CO2" but the context is completely different from what was being claimed (total human emissions so far): it's an estimate of the remaining global carbon budget from 2011 onwards for the political goal of limiting global temperature rise to 2 ̊C.

"A temperature rise of 2 ̊C is consistent with combustion and release of around 1 trillion tonnes of carbon (1000 Gt C). The 2013 IPCC Working Group 1 report calculates the remaining global carbon budget from 2011 onwards consistent with the political goal of limiting global temperature rise to less than 2 ̊C to be 300 Gt C, equivalent to emission of 1100 Gt CO2. Current known and exploitable fossil fuel reserves are equivalent to 3100 Gt CO2, three times greater than this cumulative emissions budget. A conservative estimate of the additional fossil carbon resource that could be extracted is 30-50 times greater (~45000 Gt CO2)." [1]

Their reference for that amount is "IPCC. Fifth Assessment Report Summary for Policymakers, Working Group 1: the physical science basis (2013)". [2] However when I read and search that document that particular number is absent. A search of the full 1,552 page report [3] also comes up empty.

[1] Scott. V., Haszeldine, R.S.H., Tett, S.F.B., Oschlies, A., Fossil fuels in a trillion tonne world, Nature Climate Change 5, 419–423, 2015. (https://www.nature.com/articles/nclimate2578)

The author ‘post-print’ PDF version is available through Edinburgh Research Explorer: https://www.research.ed.ac.uk/portal/files/19407404/Fossil_f...

[2] https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_SPM...

[3] http://www.ipcc.ch/report/ar5/wg1/

> these plants are in effect starved for CO2, because they evolved during time periods with much higher CO2 levels

Oh, the old argument trotted out again. What do you mean, plants "evolved" in the past and then what? Stopped evolving? If plants were starved of CO2 now they would go extinct, which they aren't. To prove my point, I present exhibit A: The Amazon rainforest.

Starvation is not equivalent to death, it means that plants are not growing as fast nor as well as they would with higher levels of CO2.

This is a proven fact and has been amply demonstrated in scientific experiments; it is related to well-understood biological processes in photosynthesis. It is the reason greenhouses deliberately increase CO2 ppm. [1] And yes, the plant kingdom has evolved just a few pathways for photosynthesis that worked well at much higher CO2 levels (10-15x current) when they originated; and these pathways are not magically "evolving" to function with diminishing CO2 levels, they've merely become suboptimal given the atmospheric conditions in the last million years, and would stop working below specific levels.

Your ignorant dismissals are moronic denials of facts and science. Surely you don't pretend that there is no lower limit to the viable amount of CO2 in the air for Earth vegetation to survive?

[1] http://www.omafra.gov.on.ca/english/crops/facts/00-077.htm#s...

this is why I have been trying to promote CO2 production to a target level of 1200PPM. With enough solar, biofuels and wind -- which are all net negative entry input vs energy output (which promotes CO2 production) I was hoping we could do this.

Apparently burning petrol releases about 2.31 kg of CO2 per liter. At 100 USD per tonne of CO2 it would cost 0.23 USD per liter of petrol if we captured every bit of CO2 released. That's within the realm of possibility.

Well that's a Holy Fuck moment for me.

I thought the parent here had made a off-by-orders of magnitude error - how can a liter of petrol (which itself is only a kg) produce 2.31kg of CO2 ... i mean work it out, all the carbon would have to attach to 2x oxygen ... ok that might just ... err ...

see this reference for a walk through of the calculation - http://ecoscore.be/en/info/ecoscore/co2

Every time I pour petrol into my tank I am basically pouring twice that weight of CO2 into the atmosphere.

I may be very dumb but I never thought if it like that before. I always assumed CO2 was a minor byproduct ... but like breathing.

oh dear.

> like breathing

When you eat 1kg of peanut butter, if I've done my math right, you'll breathe out about 2.3kg of CO2. Dry cereal would be about 1.5kg. Most foods have a lot of water in them, though.

I would think you're unlikely to produce sufficient bile to metabolise an entire kilogram of peanut butter at once. Most likely you'd get really nasty, oily runs at best, and quite possibly throw up.

Darn and that looked like a pretty decent breakfast :-)

Yes, but the weight of the oxygen is in the atmosphere already. And for a bonus, all the hydrogen you burn removes O2 from the atmosphere in the form of water, reducing the weight of the atmosphere (and therefor the greenhouse effect of the atmosphere). How much the reduction of O2 from H burning offsets the transformation of O2 to CO2 is left as a problem for the reader. If anyone knows of a paper that discusses this effect, I'd love to read it.

most of the weight is oxygen, by definition CO2

Carbon Atomic Mass: 12.0107 amu Oxygen, about 16

so carbon itself is really just 27% of CO2 12 / (32 + 12)

so you're not pouring "twice the weight of CO2" of petro, that would be wrong. Its taking 73% of the weight from the air, and putting it back, plus a little more.

The point is I am taking a locked down "harmless" fluid and doubling its weight as "harmful" gas - the weight thing surprised me.

it was just a human way to look at it

Consider it this way. That entire liter turns to gas when burned, and in doing so it combines with O2 and other things in the air, resulting in the total weight of the liter + what it combined with entering the air.

Yeah it seems pretty straightforward to just start taxing at that rate and be done with all the nonsense.

Except for the part that this process takes electricity to do. If the process can be turned off and on quickly, it would be a great use for excess wind and solar power.

One nice thing about this is that you could pull carbon out of the atmosphere from remote locations, in particular hydro electricity could provide abundant, inexpensive, and clean power.

Just what I was thinking. Like west Texas with wind where electricity prices go negative quite often in the middle of the night.

guys, capturing CO2 or not releasing it at a power plant are the easy and cheap part. It's what you do with the voluminous CO2 gas. Converting to fuel will be very expensive (although if the conversion process can be throttled quickly, which I highly doubt, we could use peak solar and wind, and treat fuel as a battery). The figures you calculate is meaningless, factories could always have been fitted with carbon capture for a relatively low energy cost. The reason this is not done at scale is there is zero demand for CO2! (unless you pay someone carbon credits to pretend to need CO2!!!)

Yes, at that scale, the price of CO2 approaches zero, especially with the caveat that it shouldn't be reintroduced (as with carbonated beverages and pressurized machinery).

Carbon dioxide sequestration or transformation is the next step. Getting the first step to be economical is also nice.

CO2 injection is already done in many oil fields for enhanced oil recovery. People already know how to pump it down into the earth and track where it goes. Put a decent price on removing CO2 from the atmosphere and people will quickly figure out how to do it for a nice profit. Lots of old oil wells in west Texas also.

A funny coincidence: the excise duty on petrol here consists of several "parts", one of which is the carbon dioxide tax, which is currently about 0.25 USD/litre (in total the fixed taxes amount to a bit over 1 USD/litre).

I assume "here" is USA, but you could be converting to dollars from local currency?

I'm converting because earlier messages used dollars as well. I doubt that taxes that high exist anywhere in the US (1 USD/litre being almost 4 USD/gallon after all).

This is a mind blowing concept. I mean, it makes sense when I read:


But does this take into account catalytic converters or other emissions controls? Cats take the CO from the combustion process and turn it into CO2, the gas you're referencing. I'd just like to clarify because this is a big revelation in my way of thinking about pollution. Are we really releasing that much CO2 post emissions controls?

Emissions controls have no effect at all on CO2 emissions. They don't alter the fundamental stoichiometry of a pure octane combustion:

2C8H18 + 2502 -> 16CO2 + 18H2O

So yes, burning a liter of octane (6 moles) will use ~1600 liters of oxygen and emit ~1000 liters of carbon dioxide, or a little over two kilograms. In pure carbon terms, it produces (drumroll) the exact same amount as the input: 49 moles at 12 g/mol or 590 grams.

Yes, I would happily pay that for "carbon neutral" gas.

Considering the US has literally entered wars that cost trillions over oil disputes, I think you are pretty much alone.

Sounds like others are paying a fairly high price in that case but just more indirectly

Counter-example: I'd happily pay at least that much for carbon-neutral or carbon-reducing fuel.

Source: Am registered-voter citizen of the United States.

I'm not disputing that, just the the political climate makes that opinion a miniscule minority.

You are making the big assumption this article is accurate and scalable. I’m not so sure.

You’re also assuming that capturing everything scales linearly from capturing something.

Bill Gates has been funding this project since its inception and one of the founders is a world expert in global warming and a Professor at Harvard so you'll have to do better than unsubstantiated innuendo here. Roll out some real facts rather just than pulled out of your ear guesses.

You realize the argument you’re making (“Smart people are backing this!”) is exactly how Theranos and many other scams go on as long as they do right?

All I did was bring up some concerns. I did not state any facts, merely point out details that need to be addressed.

Chill out.

This may give you some reassurance.[1]


Why would it? It’s just another one sided fluff piece. Basically a press release for the product much like the original article.

So they are talking about a plant, soon to be built, that will capture about 50.000 tons of CO2 per year. Amazing! A single coal fired power plant (1GW) emits 12 million tons of CO2 per year.

Seriously, this stuff won't work, and it's pointless as long as fossil fuels are burned somewhere on Earth. It's bloody obvious what to do instead: (1) stop burning coal for electricity, (2) stop burning methane ("natural" gas) for electricity, (3) stop burning methane for process heat, (4) stop using methane to make fertilizer, (5) use electrified railways instead of trucks for most transportation.

Then it makes sense to talk about synthetic fuels, CO2 capture, electrifying the remaining transportation, etc, but not before.

I agree about the priorities. But to do what you suggest, to the extend that it needs to be done, we need much better ways to cope with variability of renewables. We probably need a whole range of energy storage solutions; no single one will be sufficient. And then there are aviation and shipping, neither of which is going electric any time soon. So starting work on using excess power when renewables are over-generating to capture CO2 and using it to make carbon-neutral liquid fuels seems to also be a key part of the long-term picture.

> aviation and shipping

Another distraction. They don't matter as long as coal is being burned.

> renewables are over-generating

Even then, trying to capture a trace gas is the dumbest thing anyone could attempt. Especially if the process involves calcining lime---what a ridiculous waste of energy. Just make ammonia instead.

> Another distraction. They don't matter as long as coal is being burned.

Sure, let's kill off basically the only way to get things and people across the world. I'm sure that'll end up lovely.

This nails it. What I don't get is; why don't these companies focus on scaling production for really efficient and cost effective Co2 scrubbers that can attach to any factory exhaust ventilation system and then have governments mandate their installation or face heavy fines and penalties?

Capturing it at its source in industry would be a big start, then we just need to focus on forest clearing which is also a political issue

Pointless? I wish I could back through history, and count how many times "experts" said certain ideas and endeavors were "pointless" just to have them become reality.

Just make sure you also tally up how many times they said 'pointless' and were proven right.

Spending time and resources on things that won't work (economically) does no one any good.

"They laughed at Einstein. They laughed at the Wright brothers. But they also laughed at Bozo the Clown."

-- Carl Sagan (paraphrased from memory)

The r/science conversation crushes the HN conversation and is worth skimming.

Let's take this article at its word, which is that right now we can bury carbon for $600/tonne (forget the speculative $100/tonne) which equates to $1.32/liter of gas (based on the speculative $0.22/liter). In California right now gas costs ~$4/gallon (which is high compared to most of the US but low compared to most of the developed world), so it's not an insane amount to pay for carbon-neutral gas.

The interesting thing to me is that this is presumably something ideal to do with excess solar power (e.g. it's a much better deal than paying other states to use it, which is what California is currently doing).

Another question is how does this compare, price-wise, to using solar power to create fuel (e.g. hydrogen) and truck it around the way we do with gas.

All of the skepticism here in the top comments is well-placed.

This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or more; courtesy of the second law) as it would have to get that energy from a different source in the first place.

There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources.

Physics and thermodynamics don't actually use $ costs in their equations... e$ !== mc2

The costs you are referring to are in energy. It's entirely possible that the $ cost to put it back into the ground are cheaper than to get it out.

Hmm, mostly depends on where you put it. Putting it into ocean would probably be add hard as getting it out of there.

Except here we can put it into storage in a more convenient place.

The real problem is that we do not have enough energy to run this yet. A bunch of nuclear plants would solve it but these come with political baggage. Unfortunately CO2 recovery is very local.

Not necessarily. A portion of the energy from burning fossil fuels comes from hydrogen reactions not carbon. How much - I have no idea.

That's only true if the proposed process converts atmospheric CO2 back into an energetically dense form. This design stores it as calcium carbonate, which is nowhere near as energetic. They're not undoing the burning process to get hydrocarbons again, they're just collecting it.

> This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or more; courtesy of the second law) as it would have to get that energy from a different source in the first place.

> There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources.

This is not true.

There is no thermodynamic reason that the energy of splitting C(n)H(2n+2) + 2O(2) into water and carbon dioxide should have any connection to the energy of moving molecules of CO2 from location A to location B. If you were talking about carbon sequestration by turning it back into a hydrocarbon fuel, then yes. For carbon capture and storage, this line of thinking is wrong. Most of the CO2 sequestration strategies either rely on pressurization/containerization (PV energy is paltry compared to bond energy) or the formation of some carbonic acid ion (ionic bond energies are paltry compared to covalent bond energies).

Now, there is an issue that CO2 is severely diluted by putting it into the atmosphere. The entropic effects of dilution have to be overcome to concentrate CO2. A back-of-the-envelope estimate puts the entropy of mixing CO2 (400 ppm) into air at around 0.62 J/K, so roughly 20.4 kJ/mole CO2 are required, at least, to return it to a pure state (just taking about 3820 moles of air + CO2 and turning it into 3819 moles of air + 1 mole of pure CO2). Burning a mole of methane will produce approximately 810 kJ of energy and 1 mole of CO2 (and 2 moles of water).

So the energy produced by creating CO2 will be approximately 800,000 J/mole, while the energy required to separate CO2 at 400 ppm from the atmosphere will be approximately 20,000 J/mole. You could have a natural gas-fired CO2 concentrator (the Carbon Engineering process requires heat to regenerate their chemical absorbers, so you could get pretty high utilization of the heat of combustion) and it wouldn't be an issue. Again, this is because there's a huge difference in collecting CO2 versus breaking and forming chemical bonds. That implies that 1 mole of methane can be used to sequester less than 39 moles of CO2 from the air. Now, we assumed that we could direct energy 100% to CO2 capture (maybe not a bad assumption for a chemical "free energy" process like LiOH scrubbing), but I think it's safe to say at least that 1 mole of methane could power a plant that sequesters all of the CO2 it produces (1 mole) plus some extra.

Now, I don't work in CO2 capture, but I work with membranes and liquid separation processes, which experience similar issues when you're trying to concentrate a dilute product. I expect that it's not the energy of the separation that's an issue, but rather the capital expense required to scale a CO2 capture plant to the desired CO2 capture rate (I would guess it'd have to be tonnes per day or higher) and maintaining sufficient air flow (about 2500 tonnes of air at average global CO2 concentration are required to produce 1 tonne of CO2, or about 2.1 million m^3 of air -- 1 tonne/day => 24.6 m^3/second/(tonne/day), which is quite a lot) to the capture media that makes the process expensive. There are plenty of chemical processes (maybe fifty trillion different amine scrubber chemistries/processes, hydroxides, zeolites, base-functional polymers and membranes) to work with. For reference, a 1 tonne/day plant would be equivalent to about negative 61 cars per year.

So, it would be far more efficient to capture CO2 at the power plant than free-floating in air (this is what, e.g., chemical looping combustion attempts to achieve). That I'm aware, the two ways you could achieve this are by removing nitrogen on the inlet (N2-O2 separation, or O2 adsorption/desorption onto a selective adsorber), or removing nitrogen on the outlet (N2-CO2 separation).

So while there are practical issues in CO2 capture which might be hard to overcome, the thermodynamics of CO2 capture does at least pass the "sniff test".

"The Paris Agreement’s inclusion of 1.5°C has catalysed fervent activity amongst many within the scientific community keen to understand what this more ambitious objective implies for mitigation. However, this activity has demonstrated little in the way of plurality of responses. Instead there remains an almost exclusive focus on how future ‘negative emissions technologies’ (NETs) may offer a beguiling and almost free “get out of jail card”. This presentation argues that such a dominant focus, evident for 2 and 1.5°C, reveals an endemic bias across much of the academic climate change community determined to voice a politically palatable framing of the mitigation landscape – almost regardless of scientific credibility."

Please read: https://kevinanderson.info/blog/duality-in-climate-science/

The problem here is cultural, not scientific.

Real science about climate change is not politically palatable, NETs represent an easy way out.

And if we were trying to do real science we'd have to actually find proof of cause and effect. I still have yet to find convincing proof that CO2 is the culprit. Te level of CO2 in the ar should be addressed, but I am worried that we have culturally painted CO2 as such a bad guy that the underlying cause of global warming will never be found

The problem of climate change is the same as the obesity problem, if you phrase it like this: "There is something that is going to kill you in 20 years if you don't change your habits today".

Most people wait until they have a significant event (heart attack, they can't get up the stairs without being out of breath, etc) until they change.

I always figured it would take some sort of big event for people to change, and then when that happened, we would start working on retroactive fixes ( like sucking co2 out of the air ), rather than preventative fixes.

The thermodynamics of this seems wrong to me. You would have to burn at least a ton of oil to draw a ton of carbon from the air, probably more like 2 tons due to inefficiencies. The cost of oil is 418 dollars a ton. So to make this even remotely plausible you have to assume access to an energy source which is 4 times cheaper than oil on a cost basis. So cheap, in fact, that unburning carbon from the air would be twice as cheap as mining it out of the ground.

Let's say the thermodynamics are wrong. At some level, it doesn't matter by how much.

I think of this like a battery. Use wind power or tides even solar to create this gas. Then you have easy to transport energy that is carbon neutral as you've added no new CO2 to the air. That is the excitement, not the cost per unit of energy.

The majority of the mass (72%) of CO2 is oxygen, not carbon. By convention, the "tons" generally quoted in climate literature are carbon-dioxide, not pure carbon.

Using $418/ton of oil: $418 * (1-0.72) = $117, in striking range of the $100 target. Where renewables match or exceed hydrocarbon fuel, $100 would appear to be a reasonable price.

hypothetically, if you burn 2 tons of oil and you get out of the atmosphere 1 ton of oil equivalent to burn, then if your emission-free energy cost is 1/2 the price of oil, you break even on cost, and reach carbon neutral, no?

Alternatively, if your emission-free energy cost is same as oil, you tax oil-based energy 100% and now you reach carbon-neutral?

I don't see why it has to be 4x cheaper, clarification would be helpful.

he's estimating the energetic i.e. objective cost. If the government subsidized to the point of us stopping pumping up oil or true fossil neutral rate (ignoring the CO2 already up there, which will over hundreds of years fall back to natural levels), then we would have to manufacture our fuels... with what energy? sure in the long term I think we can use renewable, but it isn't deployed yet. The only way this makes sense is if we deploy true renewable energy, and stop allowing fossil fuel industry to masquerade as green.

Unless we stop burning fossil carbon, pulling carbon out of the atmosphere to create fuels that we will then burn makes zero sense, in terms of mitigating climate change; even if we used solar energy to do this, there would be no net decrease in carbon in the atmosphere. This only makes sense if we use a carbonless energy source and “permanently” sequester the carbon somehow.

> The result, after further processing, is a calcium carbonate pellet that can be heated to release the CO2. That CO2 could then be pressurized, put into a pipeline and disposed of underground.

I'm curious why you wouldn't just bury the calcium carbonate pellets at this point (or sell them, since they have value). Pumping CO2 underground isn't a cheap or reliable process yet as far as I can tell.

> the company is planning instead to use the gas to make synthetic, low-carbon fuels.

I suppose the answer is that the synthetic natural gas is more valuable than the calcium carbonate. Seems like adding more steps than strictly necessary though.


> In the United States, Carbon Engineering is eyeing a recently expanded subsidy for carbon capture and sequestration, which could provide a tax credit of $35 per tonne for atmospheric CO2 that is converted into fuels.

Missed this bit in the article. Regulatory arbitrage, which is a very good reason to add another step in your process, even if it's not strictly optimal.

I haven't done chemistry in years, but I think you can fairly easily reuse the calcium carbonate pellet once it has been heated. I imagine the cost of energy is significantly less than the cost of the raw resources.

Why go that far? Why not grow acres of a hardy fast growing plant like hemp or seaweed, fertilized with sewage water. Harvest and dry the plant, bale it, and stack the bales underground?

Or the Midwest farmers could bale their corn waste bury it instead of burning it.

Arizona could pipe in seawater and grow seaweed by the ton.

>I'm curious why you wouldn't just bury the calcium carbonate pellets at this point

Potassium hydroxide absorbs carbon dioxide:

2 KOH + CO2 >> K2CO3 + H2O

Calcium oxide regenerates potassium hydroxide:

CaO + K2CO3 + H2O >> CaCO3 + 2 KOH

Calcium oxide is recovered by heating:

CaCO3 + heat >> CaO + CO2

Economics and policies aside, I’m a bit skeptical about the approach described in that article regarding the use of potassium hydroxide (production, transportation) and it’s subsequent processing (to re-release the captured carbon dioxide, somehow transform it into fuel, and let people release again!?); even just the logistics would most likely be releasing a good amount of CO2 if cost is such a huge factor in this.

It just feels like the carbon dioxide released would be a substantial offset to that captured. Ultimately, it would still be viable if the net outcome is a reduction in atmospheric carbon dioxide; but I’m not convinced, at least with the approach in question, that humanity’s interest is at the top of the list.

It would be absolutely fantastic and very much appreciated if someone who knows about the actual “accounting” of carbon dioxide in this type of carbon sequestration technology can comment.

Soooo, around $100/ton.

And google says we currently pump 40 billion tons per year.

Let's ballpark:

average 5 billion per year for 100 years.

500 billion excess tons.

50 trillion dollars to remove what we've already polluted.

+ 4 trillion per year to offset what we're at already.

Yeah, nothing about that is "cheap". Maybe... slightly less astronomically expensive.

And a lot of cheap carbon capture is "pump it into the ground", which, while I'm not a geologist, but I'm guessing the petroleum folks aren't looking to hard for leaks back into the atmosphere.

But given those numbers, greening the sahara seems like a much better approach than any industrial approach.

Based purely on numbers CO2 capture seems like a plausible idea. The article cites a cost of $0.22 cents per liter of fuel to capture an equivalent amount of CO2. Based on the current 93 million bbl or roughly 15 billion liters of oil consumed every day worldwide, the cost would be around 1.2 Trillion USD per year, or 1.5% of the global GDP. A lot but within the real of feasibility.

However to achieve that in practice we would need to build enough CO2 capture plants to capture the CO2 released by all human activity, and we've been building machines that release CO2 for decades. The effort to catch up is immense. The similar company Climeworks, cited in the article, has an example of such a plant here : http://www.climeworks.com/our-products/. The DAC-18 variant, which looks like the prototype that they actually built, it is a complex 3 stories high structure with 90m^2 of ground area, and according to the product page it can capture 2460 kg per day, although that is probably under ideal conditions and in practice it could be considerably less. According to a quick search we released around 36.75 Gt of CO2 last year. To capture that, we would need to build 36.75e12/365/2460 = 41 million such plants, at the bare minimum. And that would be only break even, we'd need even more to start capturing the excess CO2 already in the atmosphere. That seems unrealistic.

Well, we could plant more trees, not deforest the Amazon.. Maybe grow some algae or something too.

Probably the most cost-effective way of sucking CO2 out of the air is planting trees on a huge scale.

We should GMO a plant that spreads in the dessert and produces energy heavy fruit (probably nuts) that can be buried.

Or maybe a tree that grows super deep and thick roots.

A user on reddit did some napkin math on the r/science submission of this article. The tl;dr is we don't have enough land area for the amount of trees needed to sequester 1,100 gt of carbon.


Trees can't do it all, but they can help a lot and are cheap and we like trees!

If you read it closely, it says we can't do it in one year, which seems overambitious...

Bubblers and tubes of algae in the sun. The bubbles stir the algae to maximize growth. Add a few goldfish to help cycle nutrients[1]. You can get the algae so thick that a test stick (plastic spoon) can't be seen beyond a centimeter deep.[2]

At this stage you can remove half of the algae each day and they'll regenerate within twenty-four hours.[3] The extracted algae biomass (mostly composed of atoms that used to be air or water) can be "upcycled" by feeding to higher organisms (fish, earthworms, etc.) or processed industrially for e.g. plastics, fuel, foodstuffs, whatever.

Ah, here we go, a few people are doing it already: http://www.iflscience.com/environment/urban-algae-farm-gobbl...

The important thing is it's cheap as heck and doesn't require fancy technology.

[1] Goldfish eat algae. Few in the tank makes it a simple aquaculture system.

[2] I looked for images of "tubes of algae in the sun" and most of them were transparent. If you can see through the tube you're doing it wrong.

[3] If conditions are optimal, otherwise you might have to be happy with 35-40%.

I'm bullish on algae but you may want to adjust your expectations. If you have a photobioreactor, with algae growing too densely to see through, in the sun, with goldfish, you're probably going to cook your goldfish.

You're talking about engineering an ecosystem, and it is fancy technology. pH, temperature, and salinity all need to be copacetic. There's a reason "everyone" does aquaponics with talapia and vascular plants. Aquaponic systems usually run at pretty abysmal water qualities, but talapia will live in mud and vascular plants don't mind having lots of nutrients in their water. Algae will have a hard time growing at that high density you're imagining if they're being shaded by murky brown water. Of course these systems will have pretty big algae blooms, but usually these are biofilms growing attached to the walls of the system, close to the surface.

If you feed the algae to other organisms, they're going to die and that carbon is going to turn into methane, which is 23 times more powerful a greenhouse gas than CO2.

There's also the matter of growing algae in tubes made of petroleum plastic. How much carbon went into mining & processing the petroleum, manufacturing your tubes, and transporting them out to where your facility is, 100 miles from the nearest Starbucks? How long will it take you to pay off that carbon debt? (If there's a biobased alternative I'd love to hear about it.)

But there are solutions as well as problems. Aquaponic systems don't have to be directly coupled, for instance. And those biofilms are much denser than planktonic growth (ie tubes). My main "research" area (calling me a researcher would be too generous) is attached growth cultivation systems, for a lot of these same reasons. Pyrolysis can be used to turn the carbon into a biochar with very low bioavailability, solving the issue with methane.


Just to clarify, bubbling doesn't maximize growth as much as keep the algae alive. Keeping high-density algae well mixed does ensure that everyone gets their turn to be in the sun. But algae can't survive in an anoxic environment, and without aeration a tall column of water will quickly become anoxic. The algae on the bottom will rot and you're back to converting CO2 into methane (which, in most systems, would come right out of the top of the tube). Additionally, aeration provides CO2; no CO2 would mean no photosynthesis.

Thanks for the detailed response!

I'm on the crackpot spectrum but I'll try not to waste your time. :-)

As I mentioned in a different sub-thread, I started looking at algae as part of a system to reprocess oceanic plastic trash into biomass, so my particular ideas and designs are probably not going to be directly applicable to CO2 sequestration.

> I'm bullish on algae but you may want to adjust your expectations. If you have a photobioreactor, with algae growing too densely to see through, in the sun, with goldfish, you're probably going to cook your goldfish.

In the context of an ocean-going plastic recycling system I hadn't thought of heat pollution before because I assumed I would have the thermal mass of the ocean in which to dissipate excess heat.

To handle it you could: reduce the infrared light reaching the tubes; chill the incoming air with e.g. Ranque-Hilsch vortex tube [1]; put radiator fins on the shade side; use heat-tolerant fish; hang evaporative coolers in between the tubes; rotate the tube assemblies.

> You're talking about engineering an ecosystem, and it is fancy technology. pH, temperature, and salinity all need to be copacetic. There's a reason "everyone" does aquaponics with talapia and vascular plants. Aquaponic systems usually run at pretty abysmal water qualities, but talapia will live in mud and vascular plants don't mind having lots of nutrients in their water. Algae will have a hard time growing at that high density you're imagining if they're being shaded by murky brown water. Of course these systems will have pretty big algae blooms, but usually these are biofilms growing attached to the walls of the system, close to the surface.

I cheat: I went to a pond and scooped up water and some of the bottom muck. Start with a viable ecosystem; in the tank it wobbles but then stabilizes; my experimental system ran for months with no adjustments.

At scale, I'd adopt a kind of evolutionary attitude, any tube that went bad would be flushed and replaced with a colony from a healthy tube. Combine that with a simple automated feedback system to help keep tubes in the optimal ranges and I think it would be pretty stable overall (depending on the failure rate of the tubes.)

If you have one seawater tank in your living room you're gonna have to paper and baby that thing. If you have thousands of simple robust ecosystems in tubes and some go bad you can just flush 'em. (And if you're worried about contaminates, chemical or biological, you can flush them through the MSO reactor. Those things are used to dispose of ordinance and chemical weapons. They really really break down molecules. Mad cow prions wouldn't make it through. Heck, you could toss the tube in there.)

Biofilms are fascinating! FWIW, in the experiment I ran the fish kept the inner surfaces of the tube pretty clear, I didn't have to do any scrubbing.

> If you feed the algae to other organisms, they're going to die and that carbon is going to turn into methane, which is 23 times more powerful a greenhouse gas than CO2.

I want to experiment with feeding the algae to compost worms. These prefer just-slightly-decayed plant matter so I am thinking they would gobble up the algae as it died. Basically, you'd drain half the water in a tube directly into one end of a worm bed. The bed filters the algae out of water which also picks up nutrients. Some of the outflow would be put back into the tubes directly; the rest would be distilled to make a high grade fertilizer and the excess water condensed and returned to the tubes.

(The worms also eat their own dead. Gruesome, but it speaks to your point about turning into methane.)

> There's also the matter of growing algae in tubes made of petroleum plastic. How much carbon went into mining & processing the petroleum, manufacturing your tubes, and transporting them out to where your facility is, 100 miles from the nearest Starbucks? How long will it take you to pay off that carbon debt? (If there's a biobased alternative I'd love to hear about it.)

Well, bioplastic.[2] I'm also looking at drying out the algae in sheets and using [some kind of] glue to bond them into a membrane, as opposed to going through a chemical process to convert them into plastic. Once you've got sheets and glue you can build your structures out of inflatables. [3]

> But there are solutions as well as problems. Aquaponic systems don't have to be directly coupled, for instance. And those biofilms are much denser than planktonic growth (ie tubes). My main "research" area (calling me a researcher would be too generous) is attached growth cultivation systems, for a lot of these same reasons. Pyrolysis can be used to turn the carbon into a biochar with very low bioavailability, solving the issue with methane.

I hadn't heard of "attached growth cultivation systems" specifically but they make a lot of sense. Just skimming the wikipedia article I think I can see a lot of low-hanging fruit in terms of efficiency gains.

Are you aware of the "Living Machine" stuff?

> Living Machine is a trademark and brand name for a patented form of ecological sewage treatment designed to mimic the cleansing functions of wetlands. ... the latest generation of the technology is based on fixed-film ecology and the ecological processes of a natural tidal wetland, one of nature’s most productive ecosystems.

~ https://en.wikipedia.org/wiki/Living_machine

To me biochar seems like a very exciting path for CO2 sequestration. Not so much on the ocean for obvious reasons, but if I had any land at all I would be trying it out.

> Just to clarify, bubbling doesn't maximize growth as much as keep the algae alive. Keeping high-density algae well mixed does ensure that everyone gets their turn to be in the sun.

Yeah, you explained it better than I did. Cheers. :-)

> But algae can't survive in an anoxic environment, and without aeration a tall column of water will quickly become anoxic. The algae on the bottom will rot and you're back to converting CO2 into methane (which, in most systems, would come right out of the top of the tube). Additionally, aeration provides CO2; no CO2 would mean no photosynthesis.

Well again, my ideas are developing in the context of a system that would have lots of CO2 already bubbling through a water column anyway. [4] If the bubbles are failing I've got bigger problems.

[1] https://en.wikipedia.org/wiki/Vortex_tube solid state; separates a presurized flow of air nito hot and cold portions. I suspect it has applications in separating gas mixtures.

[2] https://en.wikipedia.org/wiki/Bioplastic

[3] https://en.wikipedia.org/wiki/Tensairity

[4] https://en.wikipedia.org/wiki/Molten_salt_oxidation MSO converts plastic to a mixture of H2 and CO; run that through a water column and you get CO + H2O -> CO2 + H2; so now you have a bunch of hydrogen and carbon dioxide. Run that through a vortex tube to separate the gasses, send the H2 to fuel cells and the CO2 to the algae tubes... Where there used to be oceanic plastic trash there is now power and biomass.

Thank you for your detailed response as well, it's always heartening to see people chipping at these problems. FWIW I've met plenty of crackpots and you are not one of them. You become a crackpot when you can't tell the difference between what is true and what you want to be true, not when your ideas are "out there".

Regarding your experiment with the fish, I suspect this is a difference in your environment, as you alluded to. I'm out here in the desert, and it is sunny and it is hot, and if you're maintaining a low evaporation rate there's no where for that heat to go. Algae don't usually mind though. If you deploy a tube out here it'll only be so long until it gets warped and won't accept a pig (basically a plug that moves along a pipeline & cleans the sides), so I'm very interested in this idea of having the fish clean the tube. But I suspect that the same technique would go belly-up for me, pun fully intended.

I completely agree with your evolutionary approach and with using ecosystems that are already functioning. I did the desert equivalent and found my attached growth culture under a rock.

I was not aware of Living Machine but thanks for pointing it out. I think a lot about a similar concept called Algae Turf Scrubbers (http://algalturfscrubber.com/) (also trademarked), which mimic coral reefs.

You clearly have put a lot of thought into this so I hope I'm not rehashing ideas you've already dismissed, but here it goes.

You may want to consider using fungi. They are the matchless experts in breaking down toxic material, and my inkling is that they will be the ones to crack the problem of digesting plastics. Some organisms have started to do this already. Fungi have the ability to learn and adapt as individuals, so they're more friendly to this sort of engineering than most complex lifeforms. Microalgae are of course fantastic because they evolve on human timescales.

Keep in mind that plastics aren't really pure hydrocarbons. It would be very nice if they were. But they'll come with paints and stabilizers and such, and you'll end up with heavy metals and other contamination (I won't pretend to understand the intricacies here). If this ends up in your biomass then it cannot be used for agriculture. Dirty biomass is usually fine for fuel production, however. I'm sure you've thought of this though and that I would see your reasoning if I understood MSO reactors better. What happens to this waste when it leaves your reactor is another big question.

Gas separation is hard. You might consider separating the nitrogen and calling that good. The more conventional approach would be to use a pressure swing absorber but I'm taking the impression you want to use your vortex tube for cooling as well as separation. I've never tried pumping pure CO2 through an algae culture, but I believe it will become toxic at some concentration.

Rather than feeding it to worms, you might consider an anaerobic digester. You'll still produce fertilizer but you'll also be able to capture methane, which you can blend with your H2 and send to a generator instead of a fuel cell. While they have the same problems with shading as aquaponic systems, AD effluents are a very good fertilization ratio for algae. (I'm remembering a lecture here so I don't have a source to cite & don't recall the ratio, I'm afraid.) Another advantage is that they can accept wet biomass, and harvesting is often the most expensive part of the process. The methane could be blended with hydrogen and fed into an off-the-shelf natural gas generator. But I imagine that you did choose fuel cells for a reason. My personal view is that developing technologies are expensive in terms of liability, and that you can only pick a few of them. So if I were you I wouldn't put fuel cells and a novel approach to gas separation in the same design. Of course methane can be converted to hydrogen through steam reformation, or it can also be used in a fuel cell. Maybe you can even put them in the same fuel cell, I don't understand this technology whatsoever.

I've also got some more open ended questions you might find interesting to think about.

Are you planning to do this on a barge or derrick? How will your process effect the chemistry of the ocean around you? How will that effect the marine life around you?

If you're concentrating metal contamination and taking water in from the ocean, can you recovery dissolved metals? Perhaps you can combine this with desalination?

Is there a way your project can help with ocean acidification?

This talk seems to paper over a lot of problems with this system (its one of those "CO2 to methane" systems), as a TED talk does, but it's an interesting idea & related to your problem space.


You're probably aware but some people are producing hydrogen from algae. Could enhance your yield.


This is good news, esp. given the context from this spectrum article why we need some technologies like these..


I'm curious how this competes with a bunch of algae in a lake

It seems like at $94/ton CO2, we're still a long way from where this becomes viable.

At that price, to offset humanity's annual 36 Gt CO2 emissions (36 billion tons) we'd need to spend about $3.2 trillion. Per year.

Surely the cost of reducing CO2 emissions - the cost of upgrading emissions sources to alternative, lower-carbon technologies - is much less than $94/ton. And that's where we should be focusing our efforts and funding for the foreseeable future.

They say they can make synthetic fuel at $1/liter with CO2 input at $100/ton. There's plenty of CO2 available commercially at about $20/ton. If they can make synthetic fuel economically out of CO2, they should be doing that RIGHT NOW, not waiting until they've perfected the air extraction process.

They could use the money they made from the fuel to speed up R&D on the extraction process.

Y Combinator is actively looking for companies working on this. If you are working on this yoiu should consider applying.



I'm the YC partner who wrote the RFS and have been pushing this. I also went to the first conference of Negative Emissions in world (I think) in Gothenburg, Sweden last month.

It's clear that much of what is needed for this to work is coming together 1) Research on underground storage is in a great place 2) Climeworks and Carbon engineering + Klaus Lackner are the pioneering companies/researchers working on Direct-Air-capture and they've shown the technology works. 3) California recently/are currently implementing legislation that will allow companies up to $180 per ton carbon removed and sequestered. This should be more than enough to build a business doing this at scale. 4) Perhaps the most important timing question is the fast drop in energy costs driven by solar. Energy is the number once scaling cost-factor if you want to scale this up to have a material impact on the climate. Solar is the obvious choice here since there is barely any scaling costs once installed. California incentives also allows you place your installations anywhere in the world. Mojave desert would be a good place.

What is needed right now is you guys. We need entrepreneurs and founders who want to start companies building both Direct-Air-Capture technology and sequestration technologies. I've met many investors over the last 6 months are looking actively to invest in these projects.

If you are working on these technologies you can email me gustaf@ycombinator.com

Two other great resources here are



I'm convinced that whoever will build the most cost-effective way to remove carbon from the air will both have a shot at a $100B+ market while saving the earth at the same time. What could be more motivating?

Do you have any interest in algae-based solutions? (Cf. my comment in this thread I just left: https://news.ycombinator.com/item?id=17268103 )

I've done some crude experiments and "back-of-the-envelope" calculations and I think there's "something there". FWIW)

We have interest in anything where cost-efficient carbon removal is the goal.

We're not picking technologies at this point since no-one really knows. Personally, I'm more excited about Direct-air-capture than I am about bio-energy with carbon capture for a bunch of reasons. Storing carbon in oceans is also interesting. Whatever path we see as a truly scalable way (like, can you 10000x your prototype and get costs benefits for example)

Okay, cool. If I come up with anything I'll drop you a line.

I started looking at algae as a way to convert oceanic plastic garbage to something organic.

You can use Molten Salt Oxidation [1] to convert plastic to "synthesis gas" [2] then feed that through a water column to convert CO+H2O to CO2+H2, then recover the hydrogen for power and feed the carbon dioxide to algae tanks.

I was going to try feeding the algae to e.g. eisenia foetida compost worms [3] to make soil and then grow whatever in that. The basic idea was to turn oceanic plastic into biomass.

But then I learned that you can make plastic out of algae. In order to be able to scale the system (without capital) it should be designed to produce as much of its own structure (like a "reprap" self-replicating machine) as possible. The limiting factors should be CPUs and magnets (for motors.)

But this is predicated on being isolated in the middle of the ocean and not having access to capital. I can't evaluate the optimal way of using this stuff in the context of being close to the rest of the economy and with capital, as there are too many variables and I'm kind of ignorant and stupid. (In other words, in a hypothetical universe where someone gave me a big pile of money to try this, the first thing I would do is recuse myself in favor of someone who actually knew what they were doing.)

[1] An exothermic reaction https://en.wikipedia.org/wiki/Molten_salt_oxidation

[2] "fuel gas mixture consisting primarily of hydrogen, carbon monoxide, and very often some carbon dioxide" https://en.wikipedia.org/wiki/Synthesis_gas

[3] https://en.wikipedia.org/wiki/Eisenia_fetida

It's called synthesis gas for a reason, if you have syngas, catalysts, and fricktons of energy you can do a lot of things, including making precursors for plastics through Fischer-Tropsch synthesis.

What's that old saying... usually misattributed to Einstein... you can't solve a problem using the same frame of mind that created it? We have a problem of too much CO2 caused by massive deployment of complex, energy-intensive industrial facilities and processes, and they want to fix it using a fairly complex and energy-intensive industrial facility/process (with giant air blowers and all), that itself is dependent on other complex industrial processes for its manufacture, transport, construction and operation. And perpetual energy use to run the fans... I mean? Are we sure it's a net positive CO2 capture after all that? And if so, is it still a net positive after the CO2 they've captured is turned (by means of even more energy input) into "low carbon fuels" that are then burned, releasing CO2 back into the atmosphere?

I mean it's great if it works and all. I just feel like the real solution doesn't look like this.

In a few years I'll probably have grandkids and when I read this, think it increases the chance that those kids will still be able to go to Disney World in Florida, i.e. it will not be submerged.

By that time Disney world will just be a VR app you load on your 8k VirtualStation via fiber optic link with others. Disney will long have replaced all their parks with simulation because focus groups found that while consumers preferred the real park, the amount of lost park sales was less than the gains of zero liability, shutting down the park and firing those employees who were eating into shareholder profits. The park now only exists as a museum and luxury apartment homes, with paid autonomous bus tours.

FWIW either way they will be able to visit, Orlando is not on the coast and is ~100' above sea level.

Don't worry, they'll move Disney World to dry land.

"Climeworks has also opened a second facility in Iceland that can capture 50 tonnes of CO2 a year and bury it in underground basalt formations. "

Taking Oxygen from our atmosphere (the gas we need to breathe) and pump it underground after we've combined it with Carbon seems like an atrociously bad idea.

Taking CO2 out is only half the battle. We're going to need that oxygen. Pumping it into greenhouses seems better, but not very cost effective: You need to build these machines, then build the greenhouses, then transport tonnes of CO2 to the greenhouses... Seems much more cost effective to build windmills, solar arrays and the like!

Earth's atmosphere is 20.946% O2 and .047% CO2. The amount of oxygen tied up in CO2 these days is really tiny.

Good. Then we should immediately require fossil fuel companies to do this or pay for someone else to do it as well as long-term storage and insurance for the storage.

This machine does the work of six people. Unfortunately, it takes ten people to operate it.

Yep, just plant a tree or two ;)

What if we all plant 2 trees each in our lifetime?

Are these machines cheaper than trees?

Wouldn't it be likely that the greater than percentage of free CO2, the cheaper removing CO2 will get per ton? Trump's intransigence could make this technology viable.

Here's a related article that circulated in finnish media a few days ago: https://yle.fi/uutiset/osasto/news/finnish_researchers_use_a...

This is about the apparent work of a Finnish researcher to come up with a scalable way to produce fuel from air such that it can be done locally. Think gas stations producing their own gas. Right now this would be relatively expensive because of energy cost but as those drop and the technology is improved, that cost can go down.

Stuff like this not surprising for anyone that has followed news around renewables lately and a very cool side effect of the fact that renewable energy prices have been dropping exponentially for quite some time now combined with the fact that the cost of lots interesting chemical processes are primarily driven by how much energy is required. As energy becomes cheaper, those chemical processes become more feasible and the demand for more energy causes people to invest in making that cheaper further. The same economic dynamic that is causing us to destroy our planet is also producing the solutions for saving it.

For example, producing clean water is a trivial process if you have cheap energy. This is why desalination plants are popping up in lots of places where clean water is scarce and they tend to be paired with wind/solar plants. You can also produce fuels out of water and the resulting fuels, whether it is hydrogen or hydrogen peroxide, are useful ways of storing energy.

Oil is a scarce resource that is hard to procure and therefore relatively expensive. If there's an energy intensive way to produce oil from CO2, that's great news because that means it's just a matter of time before the price of that energy drops enough to make that worthwhile.

Things like this can go from being too expensive to only slightly more expensive to being magnitudes cheaper in the near future.

What I love about this is that climate change can be countered with simple economics rather than idealism. Once we stop pumping new co2 in the atmosphere for cost reasons because we found a more cost effective way to just suck it from the atmosphere, nature will do it's thing and help us revert the effects of the past centuries. We don't actually need to actively clean up the atmosphere, our planet is fully capable of doing that by itself given enough time.

Also worth pointing out that oil is used for more than just fuel. So, stuff like this is relevant even if we switch to electric vehicles. We still need to produce plastics and other materials. All of that can in principle be done with co2 harvested straight from the air as well.

It would be cool to have a country which used the rest of the world's pollution to create it's own energy.

Its not profitable to clean: even if cleaning was paid for by the government, most cleaning efforts would be commercial enterprises simulating maximum cleaning effort(like the incentive to collect rat tails will result in rat breeding farms, the "environment cleaning industry" will be most profitable with more pollution and costlier cleaning incentives/bonuses ).

It will result in encouraging more pollution and removing all safeguards(clean coal? we'll clean it up later!) towards a new industry whose main interest would be preserving pollution forever to profit from cleaning it up.

Like a pharmaceutical industry, the symptoms are more profitable than curing the disease completely.

I worry that well-meaning efforts at mass climate engineering will cause far more harm than letting nature run her course.

I'm not convinced there is a causal relationship between human activity and CO2 levels or average temperatures (ignoring urban heat island and similar effects). Sure there is a correlation, but we all know what that means. The kind of atmospheric engineering that scares me is exactly the tool that would be required to show a causal relationship.

Another point of concern is that none of the doom and gloom predictions are made by any climate model. All a climate model can do is make predictions about, well, climate. It takes an economic or some other sociological model to predict how that change in climate will affect human beings and societies, and what the costs (and benefits!) will be. Even if you trust the climate models 100% you'd be a fool to trust the economic or sociological models. How can one rationally justify an intervention is worth the cost when one can't know the cost of what is being prevented?

Sucking CO2 out of the air that we put there is not climate engineering. It is just reducing the scale of the ongoing unintentional climate engineering being carried out worldwide by our use of fossil fuels.

Obviously effective carbon capture is preferable to no carbon capture. But I think there's a reasonable concern of a runaway market removing too much carbon, or the reduction of truly sustainable energy production due to the continual reuse of carbon. It's one thing to get back to where we should be while cutting carbon use to a bare minimum, another completely to control atmospheric carbon so humans can burn more oil.

That seems like worrying about drowning when your house is on fire. Let’s put out the fire first. If the fire hoses have bad effects we can figure that out later.

You have a lot of strange beliefs. Can you back any of them to the degree that you demand of others?

Have you considered taking a skeptical approach, and looking at the arguments that you disagree with a prior? I suspect that once you do, you will be more than convinced about, e.g. humans having increased CO2 levels. If you are not convinced of even that basic fact after looking at the evidence, I would suggest that there is not evidence at all that could change your mind. I.e. this is a religious or political conviction rather than an evidence based belief.

The idea that CO2 level rises is not due to human activity is as far out there as saying you've invented a perpetual motion machine. Honestly.

I believe I am taking the skeptical approach. I've read a lot on the subject and most of what I find is appeals to fear and other emotions, for example that climate change is going to destroy the earth. Actually the Earth did quite well during the carboniferous period all things considered.

Maybe human activity is responsible for the increase in CO2. I don't deny that. They are correlated. I accept that. But maybe there is a third variable or combination of variables that is driving CO2 levels? Is that really so unreasonable. It seems awfully anthropocentric and, honestly, arrogant, to assume that human activity is the only thing that affects atmospheric composition. Perhaps you should take your own advice?

> The idea that CO2 level rises is not due to human activity is as far out there as saying you've invented a perpetual motion machine. Honestly.

No it isn't. Also, I never positively stated that it isn't.

> Maybe human activity is responsible for the increase in CO2. I don't deny that. They are correlated. I accept that. But maybe there is a third variable or combination of variables that is driving CO2 levels? Is that really so unreasonable.

Go get some equipment and stand behind a car's tailpipe sometime and you'll clear up any confusion that humans are releasing CO2... That's a really bizarre thing to be hung up on. The standard skeptic line is that the CO2 isn't a big deal, not that we're not releasing loads of it.

Human beings have been releasing CO2 for a lot longer than the Otto cycle has been around. Please spare me the ridiculous straw men. The Earth had far higher CO2 concentrations in the past than it ever has had since we evolved. Clearly human behavior is not the only possible cause of net changes in atmospheric composition.

I think what you're missing here is that climate change activists aren't concerned with "saving the earth" they are REALLY concerned with saving humanity and the current set of flora and fauna on the planet. Yes, Earth has had higher concentrations of CO2, but that was before mammals existed, so, why is that even relevant? I have a hard time believing that you think we'll all be ok if our atmosphere resembles that of the carboniferous period...

Yeah, giant dragonflies roaming the air scare the living crap out of me.


The earth will be fine. Life will be fine, though it may not include humanity or many of the species we recognise or use for food and comfort.

> Human beings have been releasing CO2 for a lot longer than the Otto cycle has been around

When there were a lot fewer human beings and each individual released far less CO2. Industrialisation has brought leverage to our use of carbon, and the rate of change has become unprecedented.

> The Earth had far higher CO2 concentrations in the past

...and has also had sea levels a hundred feet or more higher than today. Which would do what to our major cities?

Do we wait for our cities to start being lost and the outside air to feel stuffy all the time before we take this remotely seriously? Or perhaps just wait until there's immediate and catastrophic danger? (ie when it's too late to do anything about)

> human behavior is not the only possible cause of net changes in atmospheric composition

I don't believe anyone would seriously claim that, but that humanity has added to the numerous existing sources. There are now enough humans using enough carbon through vehicles, heat, light, consumer goods and all the other things of development that the ecosystem can't simply squelch the results of human activity any more. We're seeing it in a whole range of areas outside of CO2, like loss of habitats and species etc.

The Earth has a long history and much of it was been a pretty awful environment for life (no oxygen would be a bummer for us, a hellscape of lava sounds uncomfortable and so does being under hundreds of feet of ice). That has nothing to do with how we can do the math about how much CO2 we're emitting and how much the concentration of CO2 is increasing.

On a long enough timeline you're right that there is nothing we can do because among other things the Sun is going to explode, but that's a phenomenally stupid reason to suggest we shouldn't manage greenhouse gasses responsibly. Humans live on a very short timeline, but we're producing effects better fit for a geological scale timeline.

You should find better sources. If they are appealing to fear and emotion, you are not finding any science.

For example, then you wouldn't be saying silly things like you're not sure that CO2 rose is not the direct causal consequence of human activity.

I'm not saying this for my own benefit, I'm saying it for yours. If I encountered a person in real life who said that I would say much harsher things to the persons face than I am now, because I can't see you face to face I want to try to be more reserved in my approbation.

Doubting basic science while not bothering to research the reasons that it's accepted science is exactly like believeing in the invention of perpetual motion machines in that it requires first not doing basic homework then thinking that one is much cleverer than everyone else.

I hate to say it, but your posts are a great example of the generally low quality of discourse on this subject. Veiled threats of verbal beatdowns and ridiculous claims like that climate models that have to be updated monthly are as solid as Newtonian dynamics do not indicate intellectual honesty or rationality.

Just as if somebody said incredibly contrary things about well established computing principles, you are doing yourself a disservice by not doing basic research while denying well accepted technical facts.

This is not being skeptical, it's being lazy.

That said, I'm also being lazy too, because it's very hard to spoon feed basic science to those who don't want to learn it. I guess I was hoping to motivate you to take an interest in researching scientific subjects that you are willing to express uninformed opinions on, but I will accept that I have failed after your last response.

Established computing principles are theorems that are true by construction, the strongest possible form of truth.

Climate models are fancy regression fits to low quality data. We know the raw data is low quality because it requires intense amounts of adjustment before the model makers can use it.

You have correctly assessed your ability at persuasion.

> But maybe there is a third variable or combination of variables that is driving CO2 levels? Is that really so unreasonable.

I see. It's really inconvenient that all this additional CO2 is just megatons of identical molecules and comes without any discernible label that might tell where it came from......

...except that they actually do! Because photosynthesis favors the lighter C12 atom over C13, all plant material (and hence, all animal material, and all fossil fuel) have slightly lower concentration of C13, compared to other non-biological source of carbon (say, volcanic gas). If the increase in atmospheric CO2 is actually due to fossil fuels, we must witness a drop in the ratio of C13. And that's exactly what we see!


>No it isn't. Also, I never positively stated that it isn't.

Are you going to write a book called "If I Did It" next? You literally just said "No it isn't"

Edit: also, there aren't scientific claims that the Earth is going to be destroyed. Our current biosphere is going to be royally fucked up, and humans are dependent on that because we are adapted to it. Climate change will lead to massive societal problems from just food production changing in output rapdily as arable areas move and fresh water sources change their locations, not to mention weather events like sea rising over coastal cities and 100 year storms showing up every few years.

Even if we agree with your position that this issue is not man made, why wouldn't we try to stop the change? It's objectively bad for human societies

Are you going to write a book called "If I Did It" next? You literally just said "No it isn't"

I believe the "no it isn't" is meant at the comparison, not at the original question.

For the past half year I've settled out to objectively answer this question for myself. There is a lot of confusion in main-stream media but if you look more closely you'll see that the scientific evidence is paramount. If you want to take a deep dive, I think the best place is the IPCC (Intergovermental Panel on Climate Change: https://en.wikipedia.org/wiki/Intergovernmental_Panel_on_Cli...). Their estimates have historically usually been a bit conservative, but I think that is also the power of the organisation.

You can read there reports here: http://www.ipcc.ch/publications_and_data/publications_and_da...

The thing is, the more research I did, the more I realised the sheer size of the problem and complexity. There is no quick fix, we need multiple solutions and they should be interdisciplinary (we are lacking interdisciplinary solutions). Also the more research I did, the more I realised, at this moment, carbon dioxide pollution is THE biggest current threat to the existence of humanity.

I still think we can solve it, for example renewable are well on their way, and I think that we will also solve the energy-storage problem in the next decade. However we don't have any practical/profitable solutions for carbon storage at scale.

If you have specific questions or you want different sources I'd be happy to help. Also, if you feel like your opinion has changed/or not after research, please enlighten other people in a constructive way. But of course, do your own research :).

> Actually the Earth did quite well during the carboniferous period all things considered.

Yes I agree Earth, and indeed life will do well on planet earth for a long time despite climate change.

Humans on the other hand...

At around 600-1000 ppm of CO2, air begins to negatively affect human performance. This fact is not hard to test. I think most people would agree that it would be a good thing not to get to that level so that human can still have natural fresh air.

Thank you for this response. It's the first one with new information in it.

This page is quite nice for some more info:


A thing that blew my mind a few months ago...

Next time you feel you need to open windows in your apartment to get some fresh air in, it means indoor co2 is probably somewhere between 800 and 1200.

If you open all the windows to the max, or go outside, co2 ppm will lower to ~400ppm. You can't go any lower than that, and there are no air cleaners that can push it lower. This is the absolute minimum.

When your parents were young, opening windows meant bringing co2 to 350ppm.

When your grand-grand parents were young, and when old-time poets wrote about fresh air, for them it was 200ppm. Neither you or I experienced it, nor possibly ever will (without attaching ourselves to an oxygen tank).

CO2 levels have been at around 280ppm since shortly after the end of the last ice age (around 10k years ago) until we started burning coal seriously, ~1800AD. The last time we had 200ppm was during the ice age. Before writing and definitely before your grand-grand parents were young (vampires excepted).

The fallacy in your view is that the earth's climate will always be changing. In fact, before human activity pushed the earth's climate to a warming trend the earth's climate was very clearly starting to tip over into another strong cooling (ice age) trend.

Even if we manage to right the wrong with the current climate situation before the oceans rise 200 feet we will still, over the millennia, face climate trends we would like to correct for. Climate engineering is in our future regardless.

You should take a look at: https://xkcd.com/1732/

If you still think that humans are not the cause, well…

I really wish XKCD would've gone back 400,000 years instead of only 20,000 for that strip. CO2 and temperature have been higher during the longer time frame, and it would be valuable for someone to explain the bigger picture adequately.

Using a comic strip as an argument, well...

XKCD has a long history of citing their work, why can't an effective argument be made with visuals? I don't understand why the medium of the argument matters here.

There is no argument made, it's a comic strip.

There is definitely an argument made. It might not be in the form that you're looking for, but the argument is there. The graph clearly points to a high correlation between the industrial revolution and a fast and huge (relative to other changes) rise in temperatures. How is this not an argument?

Yes, very clearly, sure. You don't even know the very basics of scientific methodology, statistics, interpreting data, or critical thinking.

It's actually a graph presented in a great way. Read it

Comic or not - what a great infographic

It's a really simple explanation to refute deniers, not a scientific paper

Agreed, even if unpopular.

What puzzles me is the "climate advocates" pressing for such environmental engineering show little interest in changing their own behavior - say, more concerned about grandiose systems for removing CO2 rather than personally eradicating CO2 production from their own lifestyles (and I mean >90% reduction, not mere virtue-signaling). It takes an interest in personally influencing society & economy, putting their money where their mouth is, creating a demand for alternatives and normalizing society's [non-]production levels.

Compelling vastly impactful & ill-understood (and expensive) schemes, which a lot of smart people disagree with, is dangerous when serving largely as a counter to that which even "advocates" are unwilling to do themselves.

Be the change.

Particularly odd when someone like me is doing more to "save the earth" on a personal level than most "advocates".

What puzzles me is the "climate advocates" pressing for such environmental engineering show little interest in changing their own behavior

Why does that puzzle you? That's pretty common among humans (e.g. I've had multiple smokers trying to convince me not to start smoking). Changing one's habits is hard, even if one is convinced it should be done.

I'd argue that humans adding CO2 to the atmosphere is "environmental engineering" and designing technology to reverse that is simply cleaning up.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact