They don't claim any such thing, Bruce, and you are being disingenuous. They claim we can reverse the greatest exacerbating factor. Your assertion that "it is a natural thing" is ignoring the orders of magnitude. The natural heating of the planet due to cyclical factors, minus the exaggeration caused by anthropogenic additives, is not a major issue. Add the carbon problem, which is demonstrably a human contribution, and it breaks out of the ordinary variations by an order of magnitude.

That said, it is possible that mankind will be able to redistribute itself all over the globe, flee from new deserts and encroach on melted permafrosts and rebuild without causing major catastrophic conflicts. What's a few polar bears between friends, right? But it is not likely.

A