Nature Unbound X – The next glaciation

by Javier

Summary: The IPCC expresses virtual certainty that a glaciation is not possible for the next 50 Kyr if CO2levels remain above 300 ppm. It is the long interglacial hypothesis. Analysis of interglacials of the past 800 Kyr shows they depend on obliquity-linked summer energy, ice-volume, and eccentricity, and they end at glacial inception after ~ 6000 years of Neoglaciation-type temperature decline. The lag between orbital forcing and ice volume change indicates the orbital threshold for glacial inception is crossed thousands of years before glacial inception, and the Holocene went through that threshold long ago. In the absence of sufficient anthropogenic forcing glacial inception should take place in 1500-2500 years. The long interglacial hypothesis rests on the wrong astronomical parameter, high-equilibrium climate sensitivity to CO2, and uncertain model predictions of very long-tailed CO2decay. It is not possible to determine at present if a glacial inception will take place over the next millennia. The precautionary principle indicates we should prepare for that eventuality as it would constitute the worst catastrophe humankind has ever faced.

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Hothouse Earth

by Judith Curry

We need to raise the bar on how we think about the possible worst case scenario for climate change.

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Week in review – science edition

by Judith Curry

A few things that caught my eye this past week.

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The perils of ‘near-tabloid science’

by Judith Curry

A remarkable essay by  esteemed oceanographer Carl Wunsch.

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Week in review – science edition

by Judith Curry

A few things that caught my eye this past week.

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Climate uncertainty & risk

by Judith Curry

I’ve been invited to write an article on climate uncertainty and risk.

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The Hansen forecasts 30 years later

by Ross McKitrick and John Christy

Note: this is a revised version to correct the statement about CFCs and methane in Scenario B.

How accurate were James Hansen’s 1988 testimony and subsequent JGR article forecasts of global warming? According to a laudatory article by AP’s Seth Borenstein, they “pretty much” came true, with other scientists claiming their accuracy was “astounding” and “incredible.”  Pat Michaels and Ryan Maue in the Wall Street Journal, and Calvin Beisner in the Daily Caller, disputed this.

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