Via HuffingtonPost:

• Incredible Obama/McCain dance-off
• Funny and poignant return of the Waaaasup! guys
• Opie and the Fonz weigh in.

A new study in Geophysical Research Letters (subs. req’d), “Water-vapor climate feedback inferred from climate fluctuations, 2003–2008” analyzed recent variations in surface temperature and “the response of tropospheric water vapor to these variations.” They concluded that the “water-vapor feedback implied by these observations is strongly positive” and “similar to that simulated by climate models.” The analysis concludes:

The existence of a strong and positive water-vapor feedback means that projected business-as-usual greenhouse-gas emissions over the next century are virtually guaranteed to produce warming of several degrees Celsius. The only way that will not happen is if a strong, negative, and currently unknown feedback is discovered somewhere in our climate system.

A “warming of several degrees Celsius” = the end of life as we know it (see “Is 450 ppm politically possible? Part 0: The alternative is humanity’s self-destruction“).

While some denyers/delayers/inactivists, like MIT’s Richard Lindzen, have argued that negative feedbacks dominate the climate — all of the evidence points to amplifying feedbacks dominating (except the one negative feedback that the deniers fiercely fight, discussed below).

That was a key point of my post “Are Scientists Underestimating Climate Change, Part 1“: In the real world, key climate change impacts — sea ice loss, ice sheet melting, desertification, and sea level rise — all are either near the top or actually in excess of their values as predicted by the IPCC’s climate models. For a more recent detailed discussion of accelerating climate impacts and what that portends for the future on our current emissions path, see the new WWF report “Climate Change: faster, stronger, sooner.”

The major climate models are missing key amplifying feedbacks, some of which were discussed in “Are Scientists Underestimating Climate Change, Part II.” These feedbacks include:

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