[philipkglass]

Originally you said "Conservation of Energy is an ass. It does not care one bit. Which means we can't solve a problem with less energy than what went into creating it in the first place."

Enhanced silicate weathering is a way to draw down atmospheric CO2 with less energy than went into creating the problem. Still, perhaps it will never be deployed on a large scale if people find the proposal too scary.

That's one of the most depressing things about curbing climate change. There are a number of changes that we could have implemented to prevent the problem from getting as bad as it is now. But all of them scared enough people that they didn't go forward on a scale that was large enough, fast enough. That could be fear of physical safety (opposition to nuclear power), fear of unemployment (coal miners against cleaner power sources), fear of lost profits (businesses against carbon taxes)...

Since the scale of the problem is vast, the scope and scale of any actual solutions will be vast as well.

[robomartin]

My point is that you can't just look at chemical reactions. How much will it take in energy and resources to make it happen? That's where Conservation of Energy becomes an ass.

In other words, it's easy to talk about a solution, any solution, in isolation of what it would really take to deploy it at a scale massive enough to affect planetary level changes. Think about all of the equipment, transportation, processing, people, energy, etc. We literally can't think about things at these scales.

To go back to my super-simple argument about how the planet behaved without us polluting it further. It typically took absolutely massive storms for tens of thousands of years to reduce CO2 by 100 ppm. I use 50,000 years as an average of sorts, but the reality is that the range extends all the way out to 100,000 years for 100 ppm.

Now imagine taking all of that and proposing that we are going to do the same in 50 or 100 years, without leaving the planet, without shutting down every form of transportation, without killing every industry on the planet and without reducing population to medieval levels. That is a tall order. It's one thing to run a little microscopic test (when compared to planetary scale everything is microscopic), quite another to have the audacity to claim we know what will happen if we take it global. We could create quite an ecological mess.

The things you mention we could have done. I don't think they would have made any difference. I mean, not in terms of atmospheric CO2 concentration. Human life, definitely. 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.

That's what a lot of these simplistic conversations miss. When I say it will take an astronomical amount of energy and resources I am thinking about a process that has to reach out and grab CO2 going up tens of kilometers into the atmosphere all around the globe. We just can't do this by installing solar panels, sprinkling the beaches with chemicals, banning coal and gasoline powered vehicles and devolving into the middle ages. This is a very tough problem and one that likely has no human-scale solution, both in terms of time and resources.

That said, I don't think this is reason for depression. Imagine for a moment if we agreed on this idea that we just can't fix it. What would our conversations turn to then? Improving human life? Developing technologies to help us live with the coming changes? Cleaning-up our act to improve life locally? That and more.

I would imagine the narrative would change radically. For one thing, we would stop hearing from ignorant politicians, celebrities, deniers and zealots. Researchers would be able to work on real research rather than having to get on the bandwagon for fear of never having access to research grants and opportunities. There is no telling what advances we might make if we just stopped the insanity this has become and allowed facts, reason and real unencumbered science and engineering to float to the top. Utopia, I know.

[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.