TED talk says 12 degrees = half planet evacuated!

[eclipse]

This TED talk (remixed) says that if we get to 4 or 5 degrees, natural feedbacks (like the 'methane bomb') could take us to 12.
At that point, this popular Grist writer summarises climate science as predicting half the planet would be uninhabitable.
Is this really what climate science is saying? Could the methane feedbacks take us from 4 or 5 degrees to 12 and then dump our great grandchildren with half the planet being uninhabitable?
www.youtube.com/watch?v=pznsPkJy2x8

[David B. Benson]

eclipse --- From following Real Climate I opine not. However, even six degrees Celcius is already the end:
www.guardian.co.uk/books/2007/apr/23/scienceandnature.climatechange

[eclipse]

Oct 20, 2014 7:21:52 GMT 9.5 David B. Benson said:

eclipse --- From following Real CLimate I opine not. However, even six degrees Celcius is already the end:
www.guardian.co.uk/books/2007/apr/23/scienceandnature.climatechange

Hi David,
that's 7 years old in a 14 year 'pause' in warming that even Catalyst is starting to unpack for us. Is there anything more recent?

[Roger Clifton]

Oct 19, 2014 13:59:18 GMT 9.5 eclipse said:

Could the methane feedbacks take us from 4 or 5 degrees to 12 and then dump our great grandchildren with half the planet being uninhabitable?

Well, what do you mean by "uninhabitable"? Tell us your own vision of what 12 degrees would do - and at what latitudes, too.

[eclipse]

Severe global warming could make half the world's inhabited areas literally too hot to live in, a US scientist warned today.

Parts of China, India and the eastern US could all become too warm in summer for people to lose heat by sweating - rendering such areas effectively uninhabitable.

Steven Sherwood, a climate expert at Yale University, told a global warming conference in Copenhagen that people will not be able to adapt to a much warmer climate as well as previously thought.

The physiological limits of the human body will begin to render places impossible to support human life if the average global temperature rises by 7C on pre-industrial levels, he said.

"There will be some places on Earth where it would simply be impossible to lose heat," Sherwood said. "This is quite imaginable if we continue burning fossil fuels. I don't see any reason why we wouldn't end up there."

The 2007 report from the Intergovernmental Panel on Climate Change (IPCC) said that average temperatures could rise by 6C this century if greenhouse gas emissions continue to rise at current rates. Scientists at the Copenhagen Climate Congress this week said the IPCC may have underestimated the scale of the problem, and that emissions since 2000 have risen much faster than expected.

Sherwood told the conference: "Seven degrees would begin to create zones of uninhabitability due to unsurvivable peak heat stresses and 10C would expand such zones far enough to encompass a majority of today's population."

He said air temperature measurements were a poor guide to the true impact of global warming on people. A better assessment is "wet bulb" temperature, which combines temperature and humidity. "A warming of only a few degrees will cause large parts of the globe to experience peak wetbulb temperatures that never occur today."

www.theguardian.com/environment/2009/mar/12/global-warming-temp-rise-population

[David B. Benson]

eclipse --- Mark Lynas's "Six Degrees" is based on his year of reading paleoclimatological papers in the Oxford Library. David Archer continues to use the book as one of the two in his climatology-for-poets class at the University of Chicago. I doubt that more recent research makes any substantive changes.

[eclipse]

Hi David,
fair enough then! The way he described the Amazonian feedback reminded me of the first time I read 'Weather makers'. Yeah, serious stuff.