07/03/2015 - Currently, countries like the UK, France, the Netherlands and Germany are sweltering under a heat wave that has set a number of new all-time records.
On this issue, Stefan Rahmstorf, Potsdam Institute for Climate Impact Research:
"We currently see record-breaking heat in Europe and the Western US. This follows two of the deadliest heat waves in history in India and Pakistan last month. Man-made global warming greatly increases the number of such heat waves: for example, record-breaking hot months already occur five times as often as they would just by chance without global warming. Such heat waves often come with drought and can result in crop losses, wildfires, and human mortality. This trend will continue if greenhouse-gas emissions go on unabated."
On this issue, Dim Coumou, Potsdam Institute for Climate Impact Research:
"The current European heat wave is due to a blocking high-pressure system which creates a persistent influx of hot air from the Sahara. Such circulation patterns are occurring more often in Europe in past years, likely related to a stalling of what we call planetary waves - giant airstreams, circling the Northern hemisphere while swinging from North to South and back. Our research indicates that upper-level atmospheric flow is weakening in summertime and this makes weather situations more persistent."
Weblink to animation: Weblink to animation of current wind patterns (see here to learn more about it)
Weblink to studies:
- Trapped atmospheric waves triggered more weather extremes
- Global warming has increased monthly heat records by a factor of five
- Multifold increase in heat extremes by 2040
Further information:
- Contribution of changes in atmospheric circulation patterns to extreme temperature trends
- Summer storm weakening leads to more persistent heat extremes
- Record Heat Around the Western US, World
PIK-experts Coumou and Rahmstorf will next week debate weather extremes at a meeting of 2000 climate researchers in Paris. The meeting aims at discussing the latest state of science in the run-up of the world climate summit COP21 in Paris at the end of the year, where governments from all countries will negotiate greenhouse-gas emissions reductions.