[Isinlor]

We can quite easily, probably for less than 1T dollars [0], stop climate change with geoengineering, but nobody wants to experiment with Earth climate.

Cost analysis of stratospheric albedo modification delivery systems

> We conclude that (a) the basic technological capability to deliver material to the stratosphere at million tonne per year rates exists today, (b) based on prior literature, a few million tonnes per year would be sufficient to alter radiative forcing by an amount roughly equivalent to the growth of anticipated greenhouse gas forcing over the next half century, and that (c) several different methods could possibly deliver this quantity for less than $8B per year. [1]

Benefits, risks, and costs of stratospheric geoengineering

> Using existing U.S. military fighter and tanker planes, the annual costs of injecting aerosol precursors into the lower stratosphere would be several billion dollars.

[0] https://en.wikipedia.org/wiki/Climate_engineering#Costs

[1] https://iopscience.iop.org/article/10.1088/1748-9326/7/3/034...

[2] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/200...

[runarberg]

Is this the cost of geoengineering the entire planet or just a localized region? Does this cost include research? Is this guaranteed to work?

Scrolling the cited wikipedia article down shows that this is not without criticism including skepticism that this will work at all. I’m personally gonna remain skeptic. There is a lot of atmosphere out there, and there is a lot of CO2 in it. Spraying aerosol sounds a little like trying to stop a hurricane by exploding a nuke inside it. Not only will it do nothing to stop the hurricane, but now you’ve made the hurricane radioactive.

[Isinlor]

The entire planet and it's ongoing cost per year.

The difference between CO2 emissions and geoengineering is that CO2 just randomly happens to change Earth climate. If we start changing climate directly and intentionally we can optimize all variables for maximal effect.

I agree that it's very underdeveloped and underresearched field. That's why I put my estimate at bellow 1000 billion dollars or 1 trillion.

Compared to potential costs of the climate change it would be worthwhile to invest 1 to 10 billion $ into geoengineering research to make sure that it will work, what side effects could it have and to figure out the costs precisely. We may have already triggered tipping points in the ecosystem that will lead to substantial global warming even if we stop all emissions tomorrow.

But my original point was that geoengineering appears to be feasible. If we can do it on Earth we can do it on Venus and to some extend on Mars too.

[elihu]

We might eventually end up doing something like that if we don't get CO2 emissions under control. However, it's not a complete solution. It wouldn't do anything to address ocean acidification, for instance, which is one of the lesser-known consequences of excess CO2 in the atmosphere. That's why we really ought to be concentrating on emitting less carbon dioxide.