[DennisP]

Then you should read the book Six Degrees by Mark Lynas, who read 3000 peer-reviewed papers on the effects of climate change and summarized them, one chapter per degree.

Billions of deaths at three degrees is probably overstating things, but three degrees does bring massive food shortages and hundreds of millions of refugees. At four degrees, billions of deaths doesn't look that unlikely, and it starts getting hard to imagine how modern civilization could survive. More than that is unthinkable.

The book is a decade old but more recent work hasn't improved the outlook at all.

[Gondolin]

Of course I am not stating that billions of death would happen overnight, like if we had a supervolcano explosion.

Instead, it would be gradual, over 20-25 years. But you are right that I am overstating things, when I write billions I think 'between 100 Millions and 1 Billion'. (Recalling that over 25 years, air pollution alone is responsible for around 100 millions deaths). It would depend on the exact temperature change: 3°C or 3.5C.

And total civilisation collapse in unlikely (I hope!), except if there is a feedback factor in global warming and we head for 4°C or more.

[lazyjones]

> Then you should read the book Six Degrees by Mark Lynas, who read 3000 peer-reviewed papers on the effects of climate change

No thanks. He's a journalist and political activist, reading his foregone conclusions from selected papers he claims to have read is a waste of time.

[DennisP]

His account matches well with everything else I've seen on the subject. Well-referenced journalism isn't a bad way to get at the truth, right-wing bloviating to the contrary. And you could always look up a sampling of the sources to check up on him.

But of course, sticking with your own forgone conclusions is clearly better.