Thursday, March 26, 2015

PNS and Chinese Science


I was recently asked (from someone located in China) ‘to what extent “postnormal” conditions may acquire significance more in the democratic West than in  authoritarian countries.’ History hints that China might have had, and still has, elements of PNS. I conclude that in the end, PNS, in its current configuration, is  about power and control, no matter where one sits and, unfortunately, as a unified concept, PNS  resembles Swiss cheese, making it all the more difficult to explicitly determine exactly what it is.

Monday, March 23, 2015

Rahmstorf und Mann detektieren ungewöhnliche Abschwächung der AMOC und vermuten den Grund im Abschmelzen des grönländischen Eisschildes

An diesem Montag erschien in Nature Climate Change der Artikel

S. Rahmstorf, J.E. Box, G. Feulner, M.E. Mann, A. Robinson, S. Rutherford und E.J. Schaffernicht

"Exceptional twentieth-century slowdown in Atlantic Overturning Circulation"

Das Abstract lautet:
"Possible changes in Atlantic meridional overturning circulation (AMOC) provide a key source of uncertainty regarding future climate change. Maps of temperature trends over the twentieth century show a conspicuous region of cooling in the northern Atlantic. Here we present multiple lines of evidence suggesting that this cooling may be due to a reduction in the AMOC over the twentieth century and particularly after 1970. Since 1990 the AMOC seems to have partly recovered. This time evolution is consistently suggested by an AMOC index based on sea surface temperatures, by the hemispheric temperature di fference, by coral-based proxies and by oceanic measurements. We discuss a possible contribution of the melting of the Greenland Ice Sheet to the slowdown. Using a multi-proxy temperature reconstruction for the AMOC index suggests that the AMOC weakness after 1975 is an unprecedented event in the past millennium (p>0.99). Further melting of Greenland in the coming decades could contribute to further weakening of the AMOC."

Friday, March 13, 2015

Are emissions stabilised?

Today the International Energy Agency has published  data about last year's carbon dioxide emissions. They stand at 32.3 billion tonnes, the same as the year before.

This would be good news if it signalled a global trend, which would be a complete surprise. Stabilising carbon emissions is the goal of international climate policy which has proven elusive over the past decades. Common wisdom is that we will see many years of rising emissions globally before a plateau is in sight.

Thursday, March 12, 2015

This changes nothing - The Guardian campaign on climate change

The Guardian has embarked on a campaign to put climate change in the spotlight again. Starting last weekend it used the first pages of its print edition to publish comments by high profile campaigners like Naomi Klein, Bill McKibben and George Monbiot. These were accompanied by powerful artwork from Anthony Gormley, Nele Azevedo and Judy Watson. The motto of the campaign is 'Keep it in the ground', don't burn the vast amounts of fossil fuels that are still buried underground. Otherwise we would fry the planet.

The campaign kicked off with Naomi Klein. She asks 'What is wrong with us?'