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A Fast, Cheap and Scary Way to Cool the Planet (bloomberg.com)
79 points by JumpCrisscross 35 days ago | hide | past | favorite | 83 comments

This article doesn't address what impact this would have on crop yields if less light is reaching the surface. It also does nothing to address ocean acidification, which is realy the unaddressed elephant in the room in many climate discussions.

Olivine weathering addresses both: https://projectvesta.org/

Or the clear of forests, the rapidly decreasing biodiversity, diseases that are spreading to kill bats, trees, and bees. The rapidly increasing contamination of the ocean with plastics. The politicization of environmentalism has narrowed the focus so much. We need environmental protection on a massive scale.

There is a mention that CO2 in environment is one thing, and the temperature of the environment is another, though related.

I think Bill Gates has an opinion that we underestimate technological capabilities available for dealing with climate crisis.

Suppose we reduce solar power reaching the planet by 1%. Biosphere will get 1% reduction. How much temperature decrease we'll get and how soon?

Even with undesirable consequences another tool may be valuable to help us get where we want.

It definitely wouldn't need that much. Even blocking 1% of the sunlight would make a radical difference in the total amount of heat that hits the earth each year, but would only be equivalent to 7.2 minutes less sunlight each day on average.

As it's going right now, we're committing future generations to both CO2 removal and solar radiation management.

I think this is a very important point to understand: regardless of if you believe particular geoengineering approaches are too dangerous or too little understood to apply, at some point when the threat & the damage from global warming is no longer possible to ignore, it will not be surprising if a single actor begins unilaterally executing a relatively cheap & feasible geoengineering project:

> Solar geoengineering isn’t only technically feasible, it’s a bargain. Next to the trillions in costs from unmitigated climate change, and even the expense of cutting CO₂, solar geoengineering costs practically nothing. If anything, it’s too cheap. A program that releases SO₂ to decrease average temperatures by about 0.1C would cost less than $5 billion per year. This should prompt the world to prepare for its inevitability. Dozens of countries have both the capacity and possible motivation. The operative word is “when,” not “if.”

Ignoring the unwanted environmental side effects of pumping SO2 into the atmosphere, one thing this article does not mention is that the results of geo engineering will be non uniform. Just like global warming will causes non uniform temperature & climate change over the globe, similarly geoengineering approaches will have non uniform results -- some regions will be relative winners and some regions will be relative losers -- getting a larger share of the unwanted consequences of geo engineering with few or no corresponding benefits.

If it is going to be done, either it needs to be an internationally coordinated effort or the countries that object will treat it as an act of war.

The resulting nuclear winter should further reduce temperatures, so it's a win-win!

Possibly, though we may lack the legal framework for that - if China or Russia or the US or India decide to do some geoengineering project that takes place entirely in their airspace / territorial waters, I am not sure what the international community can do?

Which is all the more reason to acknowledge it will happen and handle it directly, instead of waiting for a rogue actor.

> the results of geo engineering will be non uniform.

The results of any climate change plan are not going to be uniform.

Importantly, the non-uniformity may have a big impact on weather patterns, leading to an increase in hurricanes and flooding and other adverse effects.

I think I saw a movie about this. They built a fast train that could survive the deep freeze by staying in motion.

But more seriously. Sunlight that hits the planet(and isn't reflected back out) is a different variable than solar heat that stays in the atmosphere. Our carbon levels are increasing the second variable. Trying to counteract that by lowering the first seems like it would have tons of unintended consequences.

I think the movie is Snowpiercer? Great movie by the way.

A few crackpot headcanonists believe it to be a grimdark sequel to Charlie and the Chocolate Factory, and given the evidence I find it hard to disagree.

It's also a TV show now as well.

You mean the sequel to Willy Wonka & the Chocolate Factory?

> Sunlight that hits the planet(and isn't reflected back out) is a different variable than solar heat that stays in the atmosphere

Solar heat that stays in the atmosphere originates from the sunlight that hits the planet and does get reflected.

The greenhouse effect is trapping the heat, not the light. So sunlight hits the atmosphere, some reflects, some more reflects off of the surface and back out, and the rest is involved in various things that eventually results in heat. That heat can then radiate out, or be trapped. Our problem is the balance of heat radiating out vs being trapped is changing. If we jump right to stopping the sunlight in the first place, sure it'll reduce the amount of heat that is produced thereby reducing the amount of heat trapped in the atmosphere, but that's not the only thing we need to consider.

On our current carbon trajectory, we're committing future generations to interventions on this scale, or to catastrophe.

A better, but more expensive idea is to build a giant sunshade at Earth-Sun Lagrange 1, a gravitationally stable point well beyond the Moon's orbit. It could be constructed with raw materials from the Moon and near-Earth asteroids, and the logistical capacity is within the design goals of SpaceX's Starship fleet.

It's expensive, and it's a giant band-aid until planetary CO2 removal is feasible. But building it would make humanity a truly interplanetary species, and benefit all of humanity for about the same cost as a city on Mars.

The giant sunshade idea is much more expensive and fragile than relatively dumb alternatives such as spraying SO2 or water into the atmosphere to deflect sunlight, I don't really understand how sunshade could be argued as a "better" solution.

Re "band-aid" -- I agree -- all solutions of this form that aim to partially mitigate one unwanted consequences of rising CO2 without addressing other consequences or halting the rise of CO2 are unlikely to result in a stable solution & instead just buy time.

A sunshade doesn't involve chemical modification of our atmosphere, and its effects are reversible (it's a solar sail and can change its orbit when required).

As to expense, it's an opportunity for the space industry to contribute to solving the #1 problem on Earth. The Starship fleet is being built anyway.

As a fringe benefit, if made of thin-film photovoltaics a sunshade could generate ~300TW of electricity. Compare that to current terrestrial consumption of 17TW. It creates enough energy and in-space manufacturing capacity to unlock the solar system.

If the sunshade has undesirable consequences, you can just move it.

It's much harder to undo terraforming attempts.

Buying time seems like a good idea

Came here to say something similar. A giant sun shade is vastly preferable to this article's approach.

Issac Arthur's podcasts are great to listen to for this sort of thing.

One reddit discussion on the concept: https://www.reddit.com/r/IsaacArthur/comments/9q6ngk/math_on...

I don't think this is actually feasible. [0] suggests you would need a mirror of 600,000 square miles (~700 miles to a side) at the L1 point to block 1% of solar radiation. And Lagrange points aren't actually gravitationally stable, you need station-keeping thrusters. Not sure how we'd go about pushing a wall of mirrors the size of France.

[0]: https://www.livescience.com/22202-space-mirrors-global-warmi...

It's a solar sail, so you can control it by differential albedo change. Here's a paper on the theory:


What's the worst that can happen if all hydrocarbons are burned?

At worst we are back in time where plankton and trees began absorbing the CO2 and turning it into oil and gas. In other words, nature will survive because such a state is well within the planet's capabilities. What am I missing?

Most people regard human extinction as a Bad Thing.

Why would humans become extinct? Somewhere on earth there will be a zone suitable for farming. At worst, only plankton and fish survive so some humans survive like Eskimos.

Sounds great.

The sunshade will be a good dry-run to solve the unavoidable problem of increasing sun luminosity in the far future, which is expected to disrupt plant life in 500 million years and ultimately destroy all life within a few billion years.

as with most things, the Simpsons did it first...

Actually Highlander 2 did it first :D https://en.wikipedia.org/wiki/Highlander_II:_The_Quickening

We jumped into global lockdowns throwing millions out of work and halving major Economies with little information on what the effects would be.

I worry if people get in a panic about global warming there could be similar rash actions that might be worse than the problem.

Mass panic feedback loops are definitely a threat we should now be aware of.

(Edit. Of course global warming is a big problem and this could be a good solution.)

Think of it another way. We've endured a harsh global economic crisis for about 380k deaths (or 0.5% mortality). The human and environmental costs of climate change could be significantly worse, and we know the cost is probably on par with the costs of the pandemic (and it can be distributed over longer time frames). We absolutely can deal with it. The problem is that a pandemic seems very urgent and scary and climate change is something that will affect us in a few decades. Dealing with it in panic mode would be very costly.

Some of these methods are surprisingly affordable. But I think it's reasonable for the time to keep them as a last ditch option. Even if we can reflect back enough sunlight, it doesn't solve pollution or ocean acidification. And I think the last thing that needs to be broadcast in Western countries is that we have a very effective way of passing the buck.

> After an attempt to stop global warming via climate engineering catastrophically backfires, creating a new ice age in 2014, the remnants of humanity have taken to a circumnavigational train, the Snowpiercer, run by recluse transportation magnate Wilford. By 2031, the passengers on the train have become segregated, with the elite in the extravagant front cars and the poor in squalid tail compartments controlled by armed guards. [1]

[1] https://en.wikipedia.org/wiki/Snowpiercer

>By 2045, humans have built weather machines to control the warming climate due to climate change and global warming. The machines break down when one day it begins to snow and doesn't stop. Whatever humans remain, live in underground bunkers to escape the extreme cold.


It was also done in The Animatrix [1]. In order to defeat the robot uprising, the world agrees to block out the sun and starve the robots of solar power. It also backfires on them.

[1] https://en.wikipedia.org/wiki/The_Animatrix#The_Second_Renai...

Geoengineering cooling concepts to counter heating due to emissions is one thing, but even when we commercialize fusion and it becomes extremely cheap to purchase huge amounts of emission-less electricity for high heat and pressure of industrial activity (exponential ramping up of metal&mineral smelting/welding/stamping/cutting/shipping) - all of this activity will be a significant source of heat.

The less toxic atmosphere of a terrestrial-based Type 1 civilization would still require planetary cooling mechanisms.

India might try this out of desperation. Major cities in India are becoming too hot to be habitable. India is a big enough country to do it alone and has a big enough problem to try it.

Reflecting insolation does nothing for the collapse of ecosystems that is the principle damage from elevated temperatures.

Ocean acidification continues increasing, soon eliminating the base of the marine food chain, and the main source of protein for much of the world's human population.

To be useful, a geoengineering program should increase bio-uptake of CO2 in the oceans, driving up the pH. This was tried in a small experiment scattering iron-containing dust, but the results were strangely confiscated and suppressed, and implausible consequences published instead. I would like to know more about the whole event, but it is hard to find out anything.

The Atlantic ocean gets a big periodic influx of iron dust from winds off the Sahara, but the Pacific doesn't.

I recently listened to Not Cool episode on geoengineering [1]. Two important points that I learned about:

- Question over who holds the dial (Russia's ok with some warming, India not so much) can easily lead to nuclear war.

- Just telling people "we're considering pumping atmosphere with a gas that causes acid rains in order to cool the planet" makes them reevaluate how serious of a problem climate change is.

[1] https://futureoflife.org/2019/09/17/not-cool-ep-6-alan-roboc...

The preamble of the movie Snowpiercer describes a the release of a chemical into the atmosphere, in an effort to combat global warming, which results in runaway rapid cooling that plunges the entire world into an eternal Ice Age.

So now life is imitates the movies (I need more popcorn!!)

We could build cooling devices on the poles. A dome around them to reflect light and (maybe) generate (some) of the necessary energy. There are well developed solutions to generate energy from waves and ocean currents. The cooling units also have pumps to essentially produce ice. The kinetic energy solutions are long snakelike tubes which can also serve to transport the

The article warns against single actors taking drastic and risky action in the future, and it's already happened with ocean fertilization: https://geog.ucsb.edu/rogue-iron-fertilization-experiment-ou...

I think this is a great idea that should not be dismissed simply out of childish fears and baseless concerns about runaway cooling and so on. At the end of the day, even if something goes wrong and we completely wreck the environment, we can always go and live on our backup planet.

Reminds me of the guy who dumped 100 tons of iron sulfate into the ocean to trigger an algae bloom in hopes of selling the carbon credits.


I love this guy. He proved that it works! Precautionary principle is riskier than it seems?

This sounds like a really great way to make solar power less efficient, make us more reliant on fossil fuels, and do absolutely nothing about the acidification of the ocean or rising CO2 levels in the atmosphere.

Marine cloud brightening. You are just lofting salt into the ocean air. Put some lofting turbines on the back of cargo ships and you have a massive and (probably!) controllable effect on albedo.

But: the sea still keeps getting more acid, so no more coral reefs and severe damage to shellfish. And once such an effort gets started, we're committed, we'll have to keep doing it.

And crop growth, ocean photosynthesis? How are those affected?

Proportionally? Say, if you reduce solar energy influx by 1%, that's how much less biosphere receives?

> if you reduce solar energy influx by 1%, that's how much less biosphere receives?

Biospheres are complex, potentially chaotic, systems.

Consider a much-less complex, less-likely chaotic, system: a company. You reduce revenues 1%. As a result, do all other line items fall by 1%? Of course not. For some businesses, if you reduce revenues by even 10% fast enough, it kills the beast.

I thought it was going to say something like accelerate our orbit so we go a few cm/km (whatever) further to balance incoming energy with outgoing...

see: Mercury vs Neptune

There is NO reliable research about this topic. Preliminary findings indicate winners and losers across world regions. It could be a source of major conflict.

Anyone have a map of the winners and losers?

A more virulent virus than covid-19 that will force world wide lock-down for at least 6months, and mortality rate of about 30%

Shading the sun like this opens the door to a very dystopic future where sunlight itself is commoditized.

Larry Niven in Ringworld had carbon nanotube dongled solar shields - that was the 70’s?

Ha, indeed, they were how they created a day/night cycle for the ring. It also provided an amazing amount of power for the ring's systems and defenses.

If we are going to talk fantasy engineering there's a perfectly good moon up there we could move into a total lunar ellipse anytime we need it, say a few days a year.

Of course by then we've mastered FTL so no need.

Could we change the inclination(?) of the moon's orbit to cause solar eclipses once a month? Would that be enough? Paging /r/theydidthemath

I'll give you this instead:



Unless we can come up with carbon neutral energy sources that are cheaper than (untaxed) fossil fuels, we are going to wind up needing something like this.

It's always fascinating that people are willing to consider geoengineering the climate of the entire planet instead of re-engineering the tax code. Tells us a lot about the system we're living in.

We can block the sun out or shoot ourselves to Mars, but apparently can't pass a law on the consumption of oil

> but apparently can't pass a law on the consumption of oil

Geoengineering requires no other change on anyone's part. Except for the funding (which could fit into any government budget with little notice), nothing changes for most people.

It feels to me that the basic idea is that something changes for pretty much all the people, but nobody really knows what.

The problem is global, so taxes in the United States that reduce fossil fuel consumption will move consumption elsewhere while incurring a political cost. It's going to be very hard to get, for example, Peru to increase its fossil fuel taxes to match.

Perhaps the United States and other rich countries could subsidize Peru and friends. The political cost for that will be very high.

It's easier to imagine and end to the world than an end to capitalism.


Carbon-neutral energy sources are already cheaper than fossil fuels. The problem is inertia.


On a bright and windy day renewables can drive the market price of electricity at the busbar below zero. You need something to fill the gap when renewables are not available. Grid scale storage is in sight but adds to the cost. Right now in U.S. And Euro zones we burn methane in gas turbines which is better than coal unless you are losing more than 1% of the methane on the way from the well.

Wouldn't it be easier to stop all economies for a month or two every year? And employ entire population to plant trees.

This proposal costs $5 billion a year. It is a heck of a lot easier than losing 8-16% of GDP.

The $5 billion figure in the article is the cost of spraying the atmosphere, creating a new virus every year would be way cheaper (I am not saying it would be a good idea). But, as it has happened with this virus, reducing sunlight would have huge effects in all economic sectors. Agriculture is the most obvious one, but tourism for example would be very affected too, real state markets may radically change, solar power would be much less efficient... It may be much less or much more than 8-16% GDP, I do not know (specially in an hypothetical scenario in which climate change may already be devastating), but for sure it would not be free.

This planet has finite resources and exponential GDP growth is dead end. Without change in a way our economies work artificially destabilizing ecosystems will only do more harm in a long term. The method in article is like using air fresheners in room full of mold.

In that case we could just use the military to engineer novel viruses and release them uncontrolled into the public. That way we could have periodic global economic shutdowns.

This buys, what, ten years of the status quo? Sooner or later carbon has to be zero (and no, carbon capture is not going to scale up to be a solution).

Reminds me of the Coronavirus lockdown. Save 0.5% of the sickest/old/obese people, cause the 99.5% to develop drug addictions, suicide, riot, undergo domestic abuse, disrupt supply chain, shortages, etc...

But look, we flattened the curve!

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