Let’s assume a few things. Whether you agree with them or not, for the purposes of this thread, let’s assume that in the aggregate we aren’t going to reduce CO2 emissions world wide by the targets the IPCC set out to keep us under 1.5 degrees C increase by 2050. The current trends are pretty much how it will play out. Let us further assume that we won’t be building a bunch of new nuclear power plants, nor will we be building 1000s of square miles of solar panels or wind farms, though the current trends on that score will continue as well. Let us further assume that battery powered cars will continue their current trends as well, but that we will still have an increasing number of fossil fuel burning ICE vehicles continuing to toss out CO2 for the foreseeable future.
IOW, assume for the sake of this thread that we aren’t going to stop global climate change by simply shutting down our technological world and the only silver bullets will be off the table for wide scale deployment because of real world reasons (i.e. we can’t build nuclear because we can’t, etc.). I know many won’t agree with the above, but if you can’t play along feel free to go to another thread.
So, the debate is…what technologies could we use to either cool the planet by blocking a percentage of the sun light or capture the carbon in large enough quantities to not only keep up with our production but to actually reduce it from 400 PPM to, oh, say 300 PPM or even more? And how feasible would they be to implement, not just cost but politically? Are there any technological solutions you can propose that might work and be feasible?
I’ll toss out a few I can think of off the top of my head. Albedo. We could basically make large parts of the earth white, somehow. This would reflect more sunlight off the planet (though I’m unsure if this would work with the green house effect becoming more prevalent). Sun shade. Basically, put a large shade or reflector at L1 to block or defuse, say, 1% of the sun light. This would be tough to do as you’d have to constantly be adjusting its orbit to ensure it stayed aligned. I also think this one would cost the most and be the most technologically challenging. Sulfur dioxide in the mesosphere. Essentially we’d be replicating what happens in a large volcanic eruption. Use large aircraft to move large amounts of sulfur dioxide into the mesosphere which would block sunlight before it gets down to where the green house effect is happening. I think this is the cheapest solution in terms of resources, but I don’t think it would be politically feasible (nor do I think the sun shade one would be either). Carbon capture. I guess this could break down into several possible scenarios including reforestation or genetic engineering of plants grown specifically to capture carbon or using artificial means to do so (though they would take massive amounts of energy which would be sort of a vicious cycle). I don’t even know if this one is possible with our current technology, though I know there have been some pilot programs for small scale tests of carbon capture equipment.
That’s about all I can think of. Maybe some combination of the above. If we could block 1% of the solar radiation hitting the earth I think it would lower the average temperature by something like .6-1.5 degrees C, which would be helpful. We’d still have the issue of too much CO2 in the atmosphere, but I think that we are on a path to eventually shift that…it’s just going to take longer than I think we have (JMHO and not part of this debate). So, what do you 'dopers think we could do?