Merkel had been welcomed by WGBU-chairman and director of the Potsdam Institute for Climate Impact Research (PIK), Hans Joachim Schellnhuber. The chancellor was especially occupied with the financial crisis these days, he said. But like rating agencies evaluate a country’s debts, “climate scientists evaluate global climate debts”. Both cases deal with a sustainable management of scarce resources, Schellnhuber pointed out. The upcoming conference Rio+20 could be a crucial impulse, he said, for the decoupling of prosperity and ever growing CO2-emissions from burning fossil fuels.
High-ranking scientists like Nicholas Stern from the London School of Economics and Leena Srivastava from the Indian TERI Energy and Resources Institute talked at the symposium in Berlin as well as representatives of the business sector like Frank Mattern, head of McKinsey Germany, or Caio Koch-Weser, vice-chairman of Deutsche Bank Group. Much applauded as a special guest was Su Wei, Director General of Climate Change at the National Development and Reform Commission of China, for his clear commitment to protecting the climate.
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For the roughly 100 postgraduates there was not only the opportunity to exchange ideas with „Mister Ozone“ Mario Molina. PIK guest scientist Ken Caldeira from the Department of Global Ecology at Carnegie Institute in Washington and professor at Stanford School of Earth Sciences talked about „intended and unintended consequences of geoengineering“ - one of several topics that were also discussed by the PhD students themselves. For the first time, this year's PhD Day was partly organized in an open discussion-format. Every 30 minutes dialogue partners switched to discuss topics like the role of scientists in public debates, CCS or biomass.
]]>Amongst the issues that were discussed, sustainable cities emerged as an area of particular emphasis for future innovation projects – from transportation systems to urban infrastructure networks. But the network’s activities won’t stop there: in addition, low-carbon production systems, climate information services and integrated agricultural and water management are all on the agenda. Currently, Climate-KIC and their partners are mobilizing roughly 100 million Euros of investments for innovation per year. This amount is planned to be scaled up considerably within the next few years.
]]>Furthermore, an accompanying book will be published this summer (Weißensee Verlag). In it, Frank Wechsung and a team of authors discuss the costs of possible climate change and adaptation measures. The Elbe approach is also tested for application on parts of river Haihe in China. Options of adaptation for the Guanting basin, one hour from Beijing, are analysed in close collaboration with local experts on water management in a region that is economically booming as much as it is affected by climate change.
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Following the visit, Matthias Platzeck said we were obliged to future generations not to abate the efforts to mitigate climate change. Grand Duke Henri showed great interest in the discussed strategies. In the course of his visit to Germany, Luxembourg´s head of state also met with President Joachim Gauck and Chancelor Angela Merkel. Amongst others, he was accompanied by the Minister of Foreign Affairs and the Minister of Economic Affairs of Luxembourg. The visit at the Potsdam Institute was a special request of the Grand Duke.
]]>This research domain is now headed by Friedrich-Wilhelm Gerstengarbe and Hermann Lotze-Campen. The meteorologist Gerstengarbe has already been a member of the PIK directorate. Lotze-Campen, an agricultural economist, worked as a senior scientist in RD I. With this new duo, RD II will focus even more on impact research, especially the effects of climate change on humankind. Extreme weather events as well as climate impacts on agriculture and ultimately food production have the potential to profoundly affect societies.
RD III "Sustainable Solutions" has expanded its management team. In addition to the economist Ottmar Edenhofer, who heads the research on climate change mitigation and, among other things, the future of the energy system, there is now the physicist Anders Levermann. He has been a group leader in RD I and started within RD III to build up research on adaptation to climate change and to explore the potential and limitations thereof.
In RD IV, complex networks and nonlinearities in natural and social systems are investigated with a strong mathematical profile. Now this is being complemented by social science research of societal metabolism dealing with partly similar dynamic processes. The mathematician Jürgen Kurths remains one of the two research domain chairs. His colleague Carlo Jäger recently retired. Now Helga Weisz who previously was co-chair of RD II now joined RD IV to become its new co-chair. She is a cultural scientist and biologist who pushes forward the analysis of socioecological systems.
]]>"A question of probabilities"
“The question is whether these weather extremes are coincidental or a result of climate change,” says Dim Coumou, lead author of the article. “Global warming can generally not be proven to cause individual extreme events – but in the sum of events the link to climate change becomes clear.” This is what his analysis of data and published studies shows. “It is not a question of yes or no, but a question of probabilities,” Coumou explains. The recent high incidence of weather records is no longer normal, he says.
“It´s like a game with loaded dice,” says Coumou. “A six can appear every now and then, and you never know when it happens. But now it appears much more often, because we have changed the dice.” The past week illustrates this: between March 13th and 19th alone, historical heat records were exceeded in more than a thousand places in North America.
Three pillars: basic physics, statistical analysis and computer simulations
The scientists base their analysis on three pillars: basic physics, statistical analysis and computer simulations. Elementary physical principles already suggest that a warming of the atmosphere leads to more extremes. For example, warm air can hold more moisture until it rains out. Secondly, clear statistical trends can be found in temperature and precipitation data, the scientists explain. And thirdly, detailed computer simulations also confirm the relation between warming and records in both temperature and precipitation.
With warmer ocean temperatures, tropical storms – called typhoons or hurricanes, depending on the region – should increase in intensity but not in number, according to the current state of knowledge. In the past decade, several record-breaking storms occurred, for example hurricane Wilma in 2004. But the dependencies are complex and not yet fully understood. The observed strong increase in the intensity of tropical storms in the North Atlantic between 1980 and 2005, for example, could be caused not just by surface warming but by a cooling of the upper atmosphere. Furthermore, there are questions about the precision and reliability of historic storm data.
Overall, cold extremes decrease with global warming, the scientists found. But this does not compensate for the increase in heat extremes.
Climatic warming can turn an extreme event into a record-breaking event
“Single weather extremes are often related to regional processes, like a blocking high pressure system or natural phenomena like El Niño,“ says Stefan Rahmstorf, co-author of the article and chair of the Earth System Analysis department at PIK. “These are complex processes that we are investigating further. But now these processes unfold against the background of climatic warming. That can turn an extreme event into a record-breaking event.”
Article: Coumou, D., Rahmstorf, S. (2012): A Decade of Weather Extremes. Nature Climate Change [DOI: 10.1038/NCLIMATE1452]
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