Comment Re: It's getting hotter still! (Score 1) 635
Concerning the Cretaceous, there is a critical factor you have not considered. The so-called fossil fuels (i.e. carbon laid down by land plants eons ago) was deposited in the Carboniferous, i.e. around 300 million years ago - i.e. before the dinosaurs.
Correct. But atmospheric carbon concentrations were actually lower during most of the Carboniferous era and reached 2000 ppm only at the beginning. And no matter how much we try, we can't actually burn all the fossil fuel deposited during the Carboniferous era because much of it has become inaccessible. There was no runaway greenhouse effect and complex, multicellular life was doing just fine during the Carboniferous era.
Atmospheric carbon dioxide reached 2000 ppm again during the Jurassic and Cretaceous periods. Again, there was no runaway greenhouse effect and complex land animals were doing just fine. And that period was recent enough that there were no significant differences in solar radiation.
"... even if we burned all of it, we'd still be on a livable planet (where do you think fossil fuel came from?)"
As I have demonstrated, it is fallacious to assert that because the fossil fuel was once non-fossil, and living things got along just fine, that it would be OK if the carbon were once again in the biosphere - what's the big deal?
My statement is correct: if burned all of the fossil fuel, we'd probably get to about 2000 ppm, the planet would be perfectly livable (and probably quite pleasant). Your calculation totaled up totally irrelevant carbon sources.
If only they'd had another few million years of evolution before getting slammed by that hunk of space rock,
The problem dinosaurs had was that they had adapted to a stable climate and therefore couldn't deal with climate change; that's why they died out when the climate finally did change.
Mammals and humans succeeded precisely because we are capable of adapting to rapidly changing conditions. That's why we have well regulated body temperatures, strong immune systems, and big brains.