Two degrees of separation

Compare and contrast:

The team's new examination of the paleo-climate record now shows that "a global warming of a couple degrees Celsius would basically create a different planet," Hansen warned. It's different than the one that humanity, that civilization knows about. If we look at the paleo record, the target of two degrees Celsius is actually a prescription for long-term disaster." [Source]

and

I think that we look at two degrees as an important and serious goal which ought to guide what we do ... it ought to inform our sense of what needs to be done. It might well cause us or anybody else to say, jeez, we need to do more. But we don't see it as akin to a national target. [Source]

The first comes from a report by KQED on warnings from top NASA climatologist James Hansen, speaking at this week's annual meeting of the American Geophysical Union. The second are the words of U.S. Climate Envoy Todd Stern, speaking at the COP17 talks in Durban, also this week.

Is Stern just having trouble staying abreast of recent events in the field that informs his job? Well, 10 months ago, a paper in the Philosophical Transactions of the Royal Society had this to say about the subject:

The analysis suggests that despite high-level statements to the contrary, there is now little to no chance of maintaining the global mean surface temperature at or below 2 °C. Moreover, the impacts associated with 2 °C have been revised upwards, sufï¬ciently so that 2 °C now more appropriately represents the threshold between 'dangerous' and 'extremely dangerous' climate change. Ultimately, the science of climate change allied with the emission scenarios for Annex 1 and non-Annex 1 nations suggests a radically different framing of the mitigation and adaptation challenge from that accompanying many other analyses, particularly those directly informing policy. [Source]

If you're a sucker for this sort of thing, read David Roberts's summary of the situation at Grist.