As someone who has been growing plants for years underwater (aquascaping) IMO geo-engineering is the only answer. We are already doing it by proxy, we need to have it front and center though. Every action has a reaction. We cannot consider a single project for its merits without the context of the larger whole. We need to not only stuff more air into that supercharged engine, we also need the correct mix of fuel, strong spark, and correct timing.

The natural way to of carbon sequestion on a planetary scale is - life ( plants / organisms / microbes etc). The catch is that if we fuck it up, and you know we will, we will pay a hefty price (like we do now with red tides, dead zones, bleeching). The added bonus is that we just do not sequester carbon, but we supercharge all the plantatary processes.

You reminded me of a "midnight thought" on the topic. I wonder if Tesla starlink process could be used to create satellites with sails that block sunlight opening/closing as needed until we can remove enough carbon to do it right? The ring of satellites could be some distance above our current satellite flight paths.

Have you ever seen the shadow of a satellite passing overhead?

For that matter, if it did work, would the satellites not reflect IR back to Earth? They might even hurt more than they help because they would be blocking sunlight on one side of the Earth only but would be blocking IR escaping on both sides.

Read about solar radiation management. Space based approaches aren't necessary. You can put the equivalent of sunblock in the upper atmosphere or seed more low clouds. It's relatively cheap but there is a lot of opposition to the science.

@dr_shiv & @DemocracyFTW (I don't recall if HN notifies of mentions)

Is the "opposition" mainly that the process as stated isn't reversible? Is there a way to improve the original idea to make it reversible in a short order?

Well, marine cloud brightening is small scale and involves lofting salt water in the air. It is immediately reversable.

The opposition comes from political signaling and tribalism.

Read more:

https://www.nature.com/articles/d41586-021-02290-3

Thank you so much - very helpful

That's not "opposition to the science", that's a sane response to a madman's proposal to intentionally f*k with the biosphere at the grandest scale.

Considering the psychological effects of no sunlight, this is a terrible idea.

It doesn't require darkened skies --a reduction in incoming light is all you need. 10% reduction would be a lot.

Oh, you'll still get sunlight, assuming you pay your monthly sunlight bill to spacex.

My response isn't a HN "appropriate" comment, more Reddit - but this is gold! Made me laugh thinking of it.

I was suggesting, more like.... if they were programmed (for instance) to open over deserts, or barren U.S. lands, etc for short periods of time. Some parts of the globe might have some small amount of light blocked for 10 mins, 1 hour, etc - whatever. It would be like a cloudy "hour", etc.

Not sure how to phrase this, but: Are you aware of clouds? (The ones in the sky, not at FAANG...)

That outcome isn't necessarily bad. It's somewhat arrogant of us to assume that we understand enough about a system as complex as the Earth's biosphere and atmosphere to know for sure a larger percentage of CO2 will necessarily be bad long term. It's feasible that it could be better, even if only after a painful transition.

I for one find the future where we're not actively managing the Earth's climate in some way to be the more pessimistic outcome. It indicates that civilization has failed to continue advancing, probably isn't spacefaring, and that the light of consciousness will eventually twinkle out once the Earth becomes uninhabitable in about 500 million years.

We'll see.

We know that, at least, thousands of species, including many not catalogged, will be driven to extinction, that large currently inhabited areas will become uninhabitable, that tens or hundreds of millions of those inhabitants will be converted to refugees unable to provide for themselves, and the influx of those refugees will drive temperate nation governments to fascism. If that is not bad enough, I can go on.

The "everything is so uncertain, we must do nothing" line has worn out its welcome. It was dishonest 30 years ago, and is reprehensible today.

Rather as in the pandemic, the attention paid to models is remarkable. You can cherry pick a model to suit your predilections. They certainly cover a wide range of possibilities. I do wonder what your view is of the utter lack of any concerted action by countries in response to these models? If we're off to hell in a handbasket, it does seem that few in power, with access to the best authorities available, are really concerned. How is that? Extinction Rebellion are certainly logical on the basis of their belief in the views of some climate scientists. They sound and act rather like people who'd say yes to O'Brien's question in 1984 when he asks Winston if he's prepared to do some pretty horrible things in pursuance of the objective of overthrowing Big Brother. But when it comes down to it, no one is convinced. Example: Coal is now back on the menu when power shortages loom.

I'm pretty sure the models are right, and that we will hit +4C on time, that politicians are aware of this, and they wont do much about it. They want to, but all real solutions have massive conflicts of interest, and they are aware voters dont really care much about global warming compared to other issues like house prices and jobs.

In forums like this, where everyone has a well paying job and fuck you money, it is important to preserve the planet, just not enough that more than 1% here would approve a build permit for a windfarm next door to their house. Arguably we mostly care about preserving the nice nature we now enjoy for free, and this is as good as it gets. The vast majority of people who specifically feel climate change is important still dont think the near guarantee of climate change is more important than the negligible risks of nuclear power.

Basically, politicians are representing the true interests of the population, which to be fair is their job. We just arent who we want to pretend we are.

Alarm about climate is overwhelming greater among voters than politicians. But US politicians (and the US Supreme Court) have arranged not to need to care if voters are alarmed, so long as lobbyists are not.

The two party system of the US occlude the matter so lets look at the rich well functioning democracies of Europe instead. Better education means there isn't anything resembling the climate denial movement of the us, and on average people are place climate concerns higher on their list of priorities. Every single one of these countries has a green party or similar whose primary purpose is the preventing ecological damage and climate change, and most argue it can be done without or with a minimum of loss of wealth and productivity. Not a single one of these countries is in a majority and most are around 10%. The ones which acknowledge that preventing a 4C rise requires massive investments and outright forced unpleasant changes will be required usually fail to go above 5%. And this is in the richest countries, the poorer countries dont give a rats ass about it, and the green parties are token efforts that idealists vote for knowing that their representatives will mostly make the others feel bad, while helping pass policy which supports the economy at the cost of eg climate as long as a token effort to minimize the negatives are used.

This shows that the vast majority of people in these countries, while publicly concerned, and privately mildly alarmed about climate change, prioritize other things and that their politicians are responding to their constituent priorities. Why would this be different in the US? everything from median education to city planning, predicts that US population cares much less about environmental impact. Poor people living on welfare in some Nordic country sometimes care about climate change, but mostly dont, certainly much less so than average citizens. The number of poor in the US who prioritize climate change over saving 5 bucks on gas so their kid can eat that night is zero.

When people aren't lying to themselves, its easy to see that preventing climate change is a policy favored by, and forced upon the public, by elites. Speaking as one, if of the lowest possible level, obviously we should do it. I'm certainly willing to sacrifice the poor both abroad and at home, but I think tigers are cool, that nature is nice to look at, and I would like to keep it that way. On the rare occasion I happen to meet some of my old friends turned politicians, I naturally point this out. And they listen, far more than they should, given neither my phd nor my career is in an applicable field. The few times I meet 0.001%ers, they have been more concerned than I. They haven't needed to status signal for decades, certainly not in private to someone like me, and they all had significant interests in industry which would be negatively affected.

This changes the story of who is preventing such policy and of if its democratic. There isn't a conspiracy by the elite to prevent climate change from being solved, if anything its the opposite, and the problem is that common people aren't stupid enough to let us get away with it.

With enough counterfactuals, you can support any claim.

The argument loses all interest, but the questions remain why the argument is being made, and who wants it made.

Your claim is that politicians prioritize global warming less than their constituents. If this was true, then in countries with multi party systems we would expect to see green parties become larger than parties which prioritize other issues. However in reality, most green parties get fewer votes than other niche voter issues like anti immigration. They are much much smaller than parties which focus on issues the voters actually prioritized, such as economy, jobs, and welfare.

People in power expect to be dead before the chickens come home to roost. They didn't get where they are by caring about what happens to anybody else. Provided civilization doesn't wholly collapse before then, they are insulated from all consequences.

All the accepted models point in the direction of mass extinctions to varying degrees.

Arrogant? It's arrogant?

You might want to read up on the effects of higher CO2 levels on human cognition. It's not pretty. And it completely blows your comment out of the water.

We already know that the CO2 levels that are forecast this century are going to be catastrophic. This isn't a "we'll see" situation anymore. We have seen. The only question is whether we will do something about it before it is far, far too late.

You need to worry about the next 50 years before you start worrying about 500 million years.

> It's somewhat arrogant of us to assume that we understand enough about a system as complex as the Earth's biosphere and atmosphere to know for sure a larger percentage of CO2 will necessarily be bad long term. It's feasible that it could be better, even if only after a painful transition.

That's the problem. Maybe it's better, maybe it's worse, and there is only one way to find out. But if it's worse, finding out is very bad. And there is no way to know ahead of time.

I think we can and should be confident about the short-medium term negative effects of high CO2 on human civilization. You can always spread doubt about anything that's long-term(say more than 2 decades) but it doesn't help to hope long-term it works, and short-term let it hurt as much as possible.