[philipkglass]

One of the things I learned --and I can't remember it accurately-- is that CO2 in the atmosphere "sticks" and is hard to mitigate. The idea is that anything we do at ground level will have zero impact past a certain altitude. We can certainly burn stuff and have the CO2 go up and circle the globe but we can't easily pull it down from 10, 20 or 30 km of altitude.

I'm not sure what you are trying to recall, but this is incorrect as written. The atmosphere stays well-mixed up to about 100 kilometers:

https://en.wikipedia.org/wiki/Homosphere

Any silicate weathering process that binds CO2 at the Earth's surface will also remove atmospheric CO2 that exists at 30 km from the surface.

The atmospheric CO2 excess was created by generations of humans all over the world. Barring breakthroughs like self-replicating machinery, fixing it will also require global scale efforts over multiple generations. I am not optimistic about people even starting serious efforts toward that end in my lifetime. My pessimism is more because of the misaligned incentives than the huge numbers involved.

If you told an engineer 150 years ago that the world would burn over 4 billion tons of coal in 2013, and asked them to plan how that would happen, it would seem impossible too. Nobody could really plan an endeavor of such scale. And in fact it didn't come from one globally coordinated plan, just a set of incentives that diffused globally. Sadly for the climate, the incentives to stop burning fossils do not spread as easily as the incentives to start.

[robomartin]

Well, destruction (burning stuff) is always easier and cheaper than cleaning it up. So what we did over 150 years, while not of a scale imaginable back then, isn't a surprise.

It's getting late. I'll check out your link later. I probably didn't word my statement correctly.

BTW, I appreciate the conversation. It is very --very-- rare that someone would engage in a mutual exploration of ideas with any degree of intelligence and critical thinking on this topic. More often than not people attack each other from opposite extremes, down-vote anyone they don't agree with into oblivion and nobody learns a thing.

BTW #2, I actually want someone to show me that I am wrong. I don't like my conclusion. I just can't find any real holes in it. And down-votes do exactly nothing towards solving that problem.