BTW, I should add that we also have a reliable number for the "no humans on earth" atmospheric CO2 rate of accumulation: It's about 100 ppm in about 10,000 yea

BTW, I should add that we also have a reliable number for the "no humans on earth" atmospheric CO2 rate of accumulation: It's about 100 ppm in about 10,000 years. In other words, on average, natural atmospheric CO2 concentration has risen at a rate five times faster than the natural "no humans" CO2 decrease rate of change. That means 0.01 ppm per year (10 ppm per thousand years). This also frames the conversation with regards to what our contribution might actually be. The challenge, of course, is that we are not going to erase humanity from the planet. Which means there will be some base number for the additional contribution to atmospheric CO2 accumulation no matter what we do. In other words, it's 0.01 ppm/yr ONLY if we evaporate from the planet. With us on this blue marble the "new normal" is far higher than that, and unlikely to ever approach the "no humans on earth" rate. This issue can be reasoned down to a few fundamental conclusions without engaging in anything more than simple analysis of the scale and timelines of the effects we are concerned with.