Believing that we'll be able to reach the 1.5°C goal[1] (much less th 2°C goal) is starting to look unscientific to me.
David Roberts put it this way:
> Basically, stopping warming at 1.5C would involve an immediate, coordinated crash program of re-industrialization, involving every major country in the world. It would be like the US mobilizing for WWII, only across the globe, sustained for the rest of the century.[2]
This is not happening and will not be happening because the the way our economic system is structured. Any country that wants to go first with the regulations needed will meet severe economic consequences. And well, time is too short for truly substantial coordination.
Deep adaptation[3] is our only hope. That and doing everything we can, considering the limitations imposed by geopolitics and our economic order, to slow things down.
I am pretty convinced nothing serious will be done. We may get lucky and technology will improve to reduce CO2 output but most likely we’ll just deal with the consequences of climate change. The world has been always been at flux so we may see refugees, wars and realignment of political power. As it has always been.
And IEA admitted that peak oil (conventional) occurred in 2008 and that shale oil may peak before 2025. Russia announced its own peak oil for 2021.
We'll be struggling soon with the worst of climate change at the same time we'll run out of fossil fuels, with no serious alternative available. This looks decidedly like the "Business as usual" World3 simulation of "Limits to Growth"...
The issue is that we seem to have triggered two positive feedback loops; methane release from melting ice and loss of Arctic albedo. This means the Earth will continue to warm even in the absence of new emissions, in a runaway fashion.
Oh my god, the ice "being gone" is basically the definition of catastrophe. If we get that far then it's way, way, way too late. Saying "once the is is gone the albedo won't get worse" is kind of like saying "eventually the plane that hits the mountain has to stop, and the crash can't get any worse".
And yes, atmospheric methane does decay in decades but the point is that before it does, it depletes sea ice and warms the ocean. The absolute worst-case scenario in a runaway climate model is something like the clathrate gun. [2]
> "One of the most eminent climate scientists in the
world, Peter Wadhams, believes an ice-free Arctic will occur one summer in the next few years and that it will likely increase by 50% the warming caused by the CO2 produced by human activity" [1]
Depends on what you mean I guess with runaway. Dinosaur age tropicals everywhere? Maybe not. Runaway as in deserts making their way into where they were not before, winters disappearing in many places we are used to having them, coastal cities having to pack up and move. Yeah, I can easily see that over a century or two.
I believe that 2 degrees is possible. Extremely difficult, but possible. There is a solution to the global coordination / first mover problem. Google for Nordhaus' climate club proposal.
The time it takes to hit 2C makes a huge difference. Pushing things back even 1 year means lots of infrastructure that needs to be replaced anyway can be rebuilt in a better location.
The trend of rapid world peace destabilization and depleting (which is somewhat disputed) oil reserves gives some hope to the radical environmentalist that world wars and famine might improve humanity's ecological footprint. What a dark time it is that we have to turn to fantasies like that to feel hopeful.
I enjoyed skimming through the Deep Adaptation paper. I expected a strategy for preventing climate crisis, but found a sobering look at how to approach it and deal with it.
> Melting permafrost effectively introduces a new country at number two on the highest emitters list, and one that isn’t accounted for in current IPCC models.
Is this correct, or is it just hyperbole? Asking because it's not like melting permafrost wasn't a known potential problem 20 years ago, so I find it dubious that IPCC models might not have factored it in already. Might it be that the IPCC models don't account for the scale of the phenomenon turning out to be worse than expected?
I'm getting extremely pessimistic about our chances at stopping this. It looks like even though we drastically reduce our emissions (which looks very much unrealistic) we haven't yet factored in all these variety of negative feedbacks that exacerbate the problem even more.
It looks more and more like the chain of negative effects like the lost albedo effect, the methane released by the melting permafrost and tons of others will create a unstoppable runaway reaction. :(
Nitpick: in system dynamics, a self-reinforcing loop is called "positive feedback", whether it is desirable or not. A "negative feedback" is a stabilizing mechanism.
People that knew about it and decided to do nothing should be prosecuted and put to jail. They wont have to live with those decisions long enough to see how disastrous they were but OUR children will..
Readers: reducing your emissions will make a difference, not just your reduction, but you will lead others, who otherwise might feel alone, to join you. And after reducing small things, you'll find it easier to reduce big things.
Eventually large number of people will reduce large amounts of emissions. Corporations, governments, and other institutions will follow.
You will make a difference. You will also find after reducing driving, flying, meat, etc, that you'll wish you had changed earlier. You replace those things with other things you like more.
There is no more time for individual action. We're about 20/30 years too late for this plan.
Positive-feedback has kicked in, so slowing down emissions will achieve very little. Because of positive feedback, even halting emissions might not be enough.
The only possible path I can think of to stem the catastrophe is a two-step plan:
1. The immediate enactment of a global carbon tax, priced high enough to materially reduce carbon emissions, and quickly.
2. Massive investment in sequestration technologies to help us scrub the air of CO2 and methane.
The challenge is colossal. Even if (1) could be done, (2) basically involves un-doing every emission of the past 20 years. Every mile driven must now be driven backwards, every good manufactured must be un-done...and with far more energy than it took the first time (thanks, thermodynamics!). And that energy must come from clean sources. And it must be done quickly; every day the carbon debt accelerates. Note, not grows — accelerates!
A friend once gave me the following metaphor. Imagine you have a glass jar, filled 1/16 with bacteria. The bacteria look up and say "we have plenty of room to grow!". Two weeks later the bacteria are half way up the jar. "Hey, it took us two week to get here, we have time to curb our growth".
So people should stop with individual action while lobbying politicans? On what do you base that? I agree that political solutions are important but can’t see that individual contributions won’t be a part of the solution. I also think that politicans usually want to do what is popular, e.g if people start eating less meat politicians dare to suggest meat taxes. Politics is usually slow, I firmly believe we need to work on all levels to mitigate co2. I’ve heard some criticism against co2 tax, since different areas of society works very differently. For example taxes on gas have not been very successful for decreasing the amount we drive even though taxes on gas in many countries are much higher than suggested tax levels for co2. Another big emitter of co2 is heating and cooling of real estate, but the cost of that is spread over a long time and is usually not payed by the entrepreneurs that build and sell the property and does not to a high degree affect the pricing. So in both of these cases we need other tools than taxes like subsidies for buying electric cars and building standards/regulations.
> So people should stop with individual action while lobbying politicians?
If it helps them lobby their politicians more, then sure. I mean, it doesn't, but if it did I'd take that trade any day.
> On what do you base that?
Purely on a sense of urgency. Individual action will--at best--lower greenhouse emissions by lowering demand for carbon intensive products & practices. How many business cycles does it take for these actions to take effect? We simply don't have decades. As well, a consequence of lowering demand of carbon-intensive products results in...a lowering of the price of carbon/oil. Increasing demand, until the slack is picked up elsewhere. The invisible hand is powerful.
A Co2 tax does the same thing as individual action--it lowers the demand for carbon, except it prevents the price from adjusting down. It is our only hope.
> For example taxes on gas have not been very successful for decreasing the amount we drive even though taxes on gas in many countries are much higher than suggested tax levels for co2.
By definition, then the tax is too low. Demand for gasoline is very inelastic, but it's not perfectly inelastic.
I don't think you understand the urgency. Runaway heating has started. We don't have 20 years. A draconianly high CO2 tax is our only hope.
> I don't think you understand the urgency. Runaway heating has started. We don't have 20 years. A draconianly high CO2 tax is our only hope.
If you believe that I don’t understand the urgency I was being unclear. What I’m saying is that when I’m been reading more on the subject I have started to believe less in a co2 tax. I much rather have for example draconian building standards because I believe that will give more bang for the buck than co2 taxes.
It's clickbait titled and split into 8 parts, for who knows what reasons, but that quote is the tl;dr version of it. Exponential growth is unintuitive, and chasing endless growth is not going to work out well for us.
Even if the bacteria find another entire jar of open space - as much space as has ever been known, as much space as they have used in their entire history - a fully terraformed Mars hanging out in the back yard previously unseen - it only lasts a single doubling-time.
Carbon sequestration seems like the (political) winner because it's much easier to convince people to spend money on something than it is to take their money for doing something (in a democratic society at least).
Edit: Of course not emitting the carbon is better and more efficient but from a practical "affecting change ASAP" perspective sequestration seems like an easier pill for society to swallow. That should go without saying but I forgot that weekends here are basically Reddit and those kinds of things cannot be considered obvious.
The idea that carbon sequestation is an alternative to reducing emissions needs to die as quickly as possible. It's rooted in fantasy, not in facts.
All climate scenarios from the IPCC that don't end up in a huge catastrophy rely on rapid emission reductions. Most also rely on carbon sequestation for negative emissions in the future (which many think is too optimistic, because it needs yet to be shown that the technology can be scaled up enough). There is no scenario of averting catastrophic heating with carbon sequestation alone.
Unfortunately we need to do both. It's much "cheaper" (in money and thermodynamics) to release carbon than to capture it, so we need to stop pumping it into the atmosphere in order for it to make any sense whatsoever to spend money removing it.
> it's much easier to convince people to spend money on something than it is to take their money for doing something
If that was the case we could have a strong carbon tax, which would actually be a very good idea, probably the most economically efficient of all. But they don't. People like to keep their money even if that means much less money for them in the long run because we don't have an economy in the sense we are used to.
I do the things listed, I don't drive, I'm vegetarian, I've stopped flying, I very rarely buy new stuff, I live in a single room but I think it's hopeless.
Without fundamental political and societal changes it feels like we're doomed. When big business can buy and amplify speech far more than concerned citizens, democracy won't be able to face/take the action needed.
You just need to fit another person in that single room, make more use of the resources to build it and need less to heat it. If the only action is shaming you for existing, because existing increases entropy, then the limit is that it goes to shaming you until you commit suicide.
It's much more important to ship 20,000 tons of Spiderman toys over the Pacific ocean for Christmas presents, only to bury them in a dump, because that's profitable. After all - you don't even buy stuff or spend money on flights or fuel, why should you even have a say or a right to exist at all? /s
Very disappointed to see so much negativity in the replies. Just wanted to add two things.
Richest 10% are responsible for half of global carbon emissions [0]. I would guess many HN readers belong to top 10%. So what we do matters.
Another good news, apparently takes only 3.5% of the population to take an active stance on something to cause a change [1]
So, don't despair. If you are already started reducing your consumption - it matters. If you haven't - it's never late to start, especially if you are rich (relatively).
And of course individual action is not mutually exclusive with lobbying politicians.
The only reason you don't despair is because you do not truly believe what the future holds. At a fundamental level you believe this is all bullshit. And with you, I of course mean us, us generally. We have various religious groups committing terrorist acts on those they believe to be their enemies. I see no evidence that the same level of 'faith' being present in any significant segment of the population.
How did we end up in this situation if it isn't an accumulation of individual actions?
Of course individual actions matter, not necessarily because of their direct impact but because of the snowball effect. Look at how green parties started 60 years ago, it was hippies and nut jobs, today they make 10-25% of votes in EU elections.
Eventually large number of people will reduce large amounts of emissions. Corporations, governments, and other institutions will follow.
I don't believe it. I don't believe cruise ship operators or aluminium smelting companies will change anything based on whether a New York or Sydney person drives less often and nitpicks about plastic food packaging. They need regulating, hard, and that means a worse economy and unhappier people with lower quality of life paying more for goods "for their own good", and that means it won't happen.
I feel it unfair that I should lead the charge to hermit-life eating leafy gruel and nitpicking over plastic lids while my brother flies halfway round the world on international holidays - and he does that because he's annoyed that he should have to care about climate emissions from an occasional holiday while business people fly over the pond for a half-day meeting and while cruise ships exist.
This is the kind of personal feeling the anti-climate-change movement has to address to get people on board, and chastising people "it'll be a catastrophe" isn't enough. I know it feels like it should be enough, but it isn't enough.
not just your reduction, but you will lead others, who otherwise might feel alone, to join you.
Only if I tell them, which I won't. The sort of people who self-promote are driving the bad things of the world - envy, aspirational Instagram lifestyles, consumerism. And the people who tell people "I'm vegan" are the butt of jokes and the hated holier-than-thou preachy people.
The people who actually will reduce their emissions will just quietly do that, like they just quietly check up on an elderly neighbour without making a fuss about how great they are for doing so. Self-sacrifice for the greater good isn't catching like shopping and showing off is.
You will also find after reducing driving, flying, meat, etc, that you'll wish you had changed earlier. You replace those things with other things you like more.
That doesn't follow. My alternatives to driving are worse than driving, otherwise I wouldn't drive right now. And I like cake more than meat - but I don't want to replace meat with cake, thanks, that would be a bad trade.
on top of what others have said, continuing to put the onus on average individuals to stop climate change is not only insulting but also counter-productive. most of us who are educated about the issues are already doing what little we can to help. while the poor are just trying to survive in a more and more unequal world. and none of that has worked. it's time for the rich and powerful to step up, time for governments and corporations to start looking past their narrow self-interest. but apparently that's not going to happen.
Im well educated and informed enough to know that anything individuals would do now is pointless..
I also understand that nothing will be done to fix the problem by powers which are able to make a difference ( because its not "profitable").
Humanity as we know it will perish. Thats why I do everything I can to enjoy the ride. Im also preparing my children, by buying properties in safer places (safer in the next 50 years..).
>Readers: reducing your emissions will make a difference, not just your reduction, but you will lead others, who otherwise might feel alone, to join you.
I'm fairly confident that every individual I personally know would react with a bemused "how quaint" if I started riding a bicycle or eating vegan or whatever as a way of fighting climate change. I'm sorry, but I just don't foresee a massive number of people changing their lifestyles voluntarily.
One real problem with the whole "go vegan" thing is that it will just be used to support additional population. Fundamentally, without managing population, all conservation really accomplishes is allowing the population to get even further out past carrying capacity.
Our society is not geared towards sustainability. It rewards overproduction and overconsumption and harshly punishes those who fail to outcompete their neighbors on these terms.
Given these constraints, what provides a greater return on your investment of time and energy? Carving out your own sustainable lifestyle within a system geared towards suppressing your efforts, or getting involved in political organizing to change the system?
I'm sorry to be so blunt, but this is pure 100% Grade A bullshit. Individual action isn't going to detectable move the needle at this point, and claiming otherwise is actively harmful. The only thing that you as an individual can do is lobby your politicians to enact systematic change at the national and global level.
Call, write, donate to those parties proposing carbon taxes, join advocacy groups for the same, form or join an interest group. Join an opinion polling group and give answers.
I don't believe lobbying as an individual is effective either. We need to participate in combined lobbying efforts to maybe exert an influence a fraction as strong as the thinly veiled (and occasionally outright) bribery committed by giant corporations and sociopathic billionaires.
Great to see more and more climate related posts on HN. Posted this a couple of times already, but I'd encourage everyone to check this paper[0] that recently came out ("Tackling Climate Change with Machine Learning").
Among one of the initiatives mentioned is a startup called Tomorrow [1] that integrates with services (Uber, Instacart, etc) to calculate your personal CO2 emissions. They need help to get more of these integrations and more CO2 models. Consider giving a hand to them or other projects like this one [2].
Another BBC story linked in the article has these amazing claims:[1]
* 2005 "NASA scientists successfully revived bacteria that had been encased in a frozen pond in Alaska for 32,000 years. ... Once the ice melted, they began swimming around, seemingly unaffected."
* 2007 "scientists managed to revive an 8-million-year-old bacterium that had been lying dormant in ice, beneath the surface of a glacier in the Beacon and Mullins valleys of Antarctica"
* 2007 "bacteria were also revived from ice that was over 100,000 years old."
Methane that will be released from Siberia is equal to hundreds of years of modern industrial activity, and can be released in a span of years. Warming is unstoppable, second order effects are already happening. Thinking that we can do anything about it is naive.
> Warming is unstoppable, second order effects are already happening. Thinking that we can do anything about it is naive.
This is probably true. However, it is possible—if highly unlikely—that something could be done. This would involve effectively halting CO2 emissions in the next 10 years and massive investment in carbon sequestration research.
Is this likely to succeed? No, not really. But why on earth would we be spending our time trying anything else?
(Well, I guess we could be spending that time preparing for the coming changes. Which we should also do.)
Anything that involves halting CO2 emissions is not something that “could be done” anytime soon except in theory. Coordinating at that scale across the globe will simply never happen, and the sooner we admit it the sooner we can move on to figure out how to deal with it not happening.
CO2 emissions will reduce to the extent that alternatives become cheaper, better and more convenient. And while that’s moving forward it won’t happen fast enough to prevent the problem from getting worse in the mean time.
So let’s stop kidding ourselves and prepare for what’s coming, both in terms of dealing with the consequences and finding ways to counteract the effects of ongoing fossil fuel usage.
I don't disagree with this comment, except insofar as I think there's room for both. Even a partial success on the mitigation side buys us more time on the adaptation side.
On a personal note, what steps do you think an individual can do to prepare for what's coming as an individual/family?
I agree, the more we can reduce emissions the smaller the resulting problem we need to solve.
On a personal level I would look at where you live and how that area is likely to change over the next 20-30 years if the current trends continue. And then either consider moving somewhere else or see what you need to do to deal with more extreme versions of floods, draughts, fires, tornadoes, hurricanes, etc.
And at the same time people imagine "colonizing" Mars and interstellar travel and other such nonsense (which requires not only similar levels of effort and global cooperation as solving the climate crisis to achieve, but also has tons of unsurmountable problems and solutions expect to be discovered and mature just because we want them - and all of that at the same time the climate is collapsing, which will force less, not more, cooperation, and less, not more turn to "every state for itself").
Yes. And while we humans deserve every bit of suffering and pain on our way, it really gets me that we will take so many innocent non-human lives and homes with us on that inevitable journey.
Collective guilt, there was no mechanism in religions of the world for it. Individual responsibility seems too low of an abstraction for that, no matter how good it worked to enable modern society.
> The Northern Hemisphere winter of 2018/2019 was dominated by headlines of the “polar vortex”, as temperatures plummeted unusually far south into North America. [...] What such stories masked, however, was that the opposite was happening in the far North, beyond the Arctic circle. [...] In November, when temperatures should have been -25C, a temperature of 1.2C above freezing was recorded at the North Pole. [1]
In November... 2018? Why do they link to an article from November 2016?
Removing material from the atmosphere is a constant process that requires vast amounts of energy. Would there be any benefit from altering the albedo of the land instead of the upper atmosphere? By laying down white reflective material solar radiation can reflected away but this constant reflection of sunlight requires no energy besides making sure the surfaces stay clear of dirt or debris deposited by the wind. Wouldn't this be an ideal solution in places like Australia that have vast deserts and suffer from extremely high temperatures?
Do they need to operate the cleaners manually? It seems like with just a couple of adjustments those cleaners could be automated and not requite a two people operating them. They could be scheduled to run once a day, every day, half an hour before the sun comes up. One sweep back and forth and the job is done. You just need to build a few more, give them a timer and two motors, and maybe make those solar panels rows longer so you need less cleaning robots. And that's it.
They could even be themselves solar powered, charging during the day when they are not working. And those people who operate them could instead go around after the "robots shift" to check for problems and fix them.
Tangential, but will increasing temperatures make lands habitable for a um... billion climate refugees? Has there been any research on that? Maldives started saving up for a new homeland in 2008, exploring India, Sri Lanka and Australia.
Whenever these articles come up the focus is on behavior changes and policy. What about good old fashion ingenuity? We know volcanos and nuclear winter can cool the planet so why not start there and work backwards? Controlled volcano eruption, generate the effects of nuclear winter without the radiation and contamination. Or even do something in space with asteroids to block the path to the sun occasionally or something else. I'm sure there are a ton of options but I rarely see any mentioned.
Remote controlling asteroids? I don't want to come across as too condemning, but my belief is that Californian[1] technoutopianism[2] is one of the more worrying trends in thought right now. It risks obfuscating real and meaningful actions needed to be taken ASAP. At its core it's often unscientific but masks itself as the belief in science, hence circumventing some much needed critique.
It has to be. There are too many competing interests. For one, Russia would welcome global climate heating due to their land being mostly frozen. Humans can't collectively come together on this issue.
As a software engineer I am very sceptical of this approach. There is no integration or acceptance environment to test it. We’ll have to do it in production and we all know how well it works.
Obviously it would be nice if a crack team of scientists and engineers ordered some pizzas and had a marathon science session that comes up with something that solves all our problems and lets us continue burning fossil fuels as usual.
But that's simply not how it works, no matter how much money you throw at it. And you won't even have money to throw at it in the US at least, because belief in climate change is a political opinion.
> in the US at least, because belief in climate change is a political opinion.
Which is a strange state of affairs. In the European countries I am familiar with, all the mainstream parties agree with core mainstream science. Their voters largely do as well. They may have more or less credible plans to address the problem but they don't have their own private scientific conclusions.
Why is the US (and maybe Australia?) different? Is it because voters are ignorant or short termist, and politicians follow? Or politicians are corrupted and mislead their voters? Or just a higher level of scientific ignorance all around? Or a heavy dependence on fossil fuel prosperity in key districts?
Can someone suggest the answer? Clearly Europeans are not more intrinsically virtuous or sensible.
Well, do they? The science is telling us that global pollution is an existential threat to humanity and that immediate drastic action must be taken. Which parties are behaving as if they believe that? Maybe Green parties are, but they aren't in power. Which parties in power are BEHAVING (not talking) as if they believe the science?
This:
Talk: "We believe in climate change"
Action: "Going to increase fuel mileage standards by 1%, that'll do it"
Even Green parties don't really believe it, because they're opposed to the only workable plan that isn't "let's all live like third world peasants": massive scale-up of nuclear fission energy.
I can't speak to Australia, but in the US I see two significant factors. The first is the news and the second is the evangelical christian movement. IMO, both are rooted in perverse interpretations of the first amendment.
My understanding is that Reagan struck down laws regarding truth in journalism, which really set the stage. Fox News is particularly egregious in climate denial (as well as fearmongering about Muslim folks, immigrants, etc.), and for many, that's just the start of a slippery slope. Smaller, especially local radio, talk-shows around the country are even more egregious. They use fear-based arguments to significant effect, and because politicians use these arguments, they're "political opinions."
The evangelical movement (which gets a lot of play on Fox and other platforms) has positioned itself as anti-science: anti-climate, anti-vax, anti-evolution, anti-lgbt. So these opinions are elevated beyond "political opinions," they're sitting on the lofty perch of "religious beliefs" and challenging them is an assault on religious liberty.
I would add Canada to that list as well. The current federal government has been trying to enforce a national carbon tax which has so far been met with siginificant resistance.
> Is it because voters are ignorant or short termist, and politicians follow? Or politicians are corrupted and mislead their voters? Or just a higher level of scientific ignorance all around? Or a heavy dependence on fossil fuel prosperity in key districts?
All of the above? :) And probably also corporate lobbying.
American immigrant to Canada: they consume Fox News here too. The station can't broadcast here, but the internet is everywhere. Canadians don't believe me when I say "Canadian politics seem to follow American politics by 5-10 years" but... I've had to update that to "1-10" years because Trump's impact on Canadian culture and politics was almost immediate.
We could get all the robots on a island together and have them shoot their exhaust fans simultaneously. This could move the earth a little further away from the sun, thus solving the problem
In a couple years, we send an email to president Warren asking her to create a new regulation that would require the FAANG companies to buy up the biggest oil, coal and gas companies and then shut their operations down. No more oil wells or coal mines!
p.s. pro tip: sell all of your Amazon, Google and Apple stock before we send out that email
If you get too extreme with your smoke in the atmosphere, you'll impact the flora. It always grows back after the smoke clears and the ice age ends, of course, but this time it would wipe out most of the fauna that depend on it, including that pesky primate infestation that caused all this. Maybe that's what we need anyway, a hard reboot.
No, there aren't. Explaining why would be way beyond the scope of an HN comment, but consider this: if it were really as easy as you imply, don't you think someone who actually knew what they were doing would have put forth a detailed plan by now?
Well they stopped emitting CFCs and the ozone hole finally started to trend smaller twenty years later[1]. Presuming China doesn't go overboard with the illegal production that's been discovered, ozone should be back to pre 1980 levels by about 2075 or so. The fix needs a century to work.
I think it neatly encapsulates the problem. Climate is big. Changes have huge hysteresis. The only real fix is emissions (lack of). What we've already emitted will be causing change for centuries. Any climate engineering is likely to be hilariously easy to over or under-shoot except carbon capture and storage. CCS is almost certainly going to be necessary as we likely need negative emissions now. At least CO2's role in the climate is becoming very well understood, and we know exactly how to fix an overshoot.
I feel like the community is slowly (edit: actually, not that slowly) changing their opinion. We were far to optimistic in our belief in the politicians.
All but the worst of the current IPCC scenarios require some sort of carbon capture even now, and the IPCC reports in general are very optimistic (what we know for sure is less bad than what we suspect might be true).
Carbon capture is classified as a climate engineering technique, and depending on how you do it it is feasible to accurately estimate the consequences. On the other hand, all techniques talked about so far need to be deployed on a massive scale, costing us a lot of resources, space and probably biospheres. The best cost estimates I've seen so far is ~200€/ton CO2 in monetary terms. The problem is that right now the research is not at the level it needs to be (another Manhattan project would be good), since there is no money in it.
Solar management techniques are indeed hard to consider, and would need to be kept up forever, which means that as soon as a war or just recession happens, we'd still be doomed, so this can only be used to buy some time and will probably have severe side-effects.
David Roberts put it this way:
> Basically, stopping warming at 1.5C would involve an immediate, coordinated crash program of re-industrialization, involving every major country in the world. It would be like the US mobilizing for WWII, only across the globe, sustained for the rest of the century.[2]
This is not happening and will not be happening because the the way our economic system is structured. Any country that wants to go first with the regulations needed will meet severe economic consequences. And well, time is too short for truly substantial coordination.
Deep adaptation[3] is our only hope. That and doing everything we can, considering the limitations imposed by geopolitics and our economic order, to slow things down.
[1] https://en.wikipedia.org/wiki/Special_Report_on_Global_Warmi...
[2] https://twitter.com/drvox/status/1049114118270197760
[3] https://www.lifeworth.com/deepadaptation.pdf