Global warming has increased monthly heat records by a factor of five

Source:  http://www.pik-potsdam.de/news/press-releases/monatliche-hitzerekorde-haben-sich-durch-die-erderwaermung-verfuenffacht

 

01/14/2013 - Monthly temperature extremes have become much more frequent, as measurements from around the world indicate. On average, there are now five times as many record-breaking hot months worldwide than could be expected without long-term global warming, shows a study now published in Climatic Change. In parts of Europe, Africa and southern Asia the number of monthly records has increased even by a factor of ten. 80 percent of observed monthly records would not have occurred without human influence on climate, concludes the authors-team of the Potsdam Institute for Climate Impact Research (PIK) and the Complutense University of Madrid. 

 

“The last decade brought unprecedented heat waves; for instance in the US in 2012, in Russia in 2010, in Australia in 2009, and in Europe in 2003,” lead-author Dim Coumou says. “Heat extremes are causing many deaths, major forest fires, and harvest losses – societies and ecosystems are not adapted to ever new record-breaking temperatures.” The new study relies on 131 years of monthly temperature data for more than 12.000 grid points around the world, provided by NASA. Comprehensive analysis reveals the increase in records.

The researchers developed a robust statistical model that explains the surge in the number of records to be a consequence of the long-term global warming trend. That surge has been particularly steep over the last 40 years, due to a steep global-warming trend over this period. Superimposed on this long-term rise, the data show the effect of natural variability, with especially high numbers of heat records during years with El Niño events. This natural variability, however, does not explain the overall development of record events, found the researchers.

Natural variability does not explain the overall development of record events

If global warming continues, the study projects that the number of new monthly records will be 12 times as high in 30 years as it would be without climate change. “Now this doesn’t mean there will be 12 times more hot summers in Europe than today – it actually is worse,“ Coumou points out. For the new records set in the 2040s will not just be hot by today’s standards. “To count as new records, they actually have to beat heat records set in the 2020s and 2030s, which will already be hotter than anything we have experienced to date,” explains Coumou. “And this is just the global average – in some continental regions, the increase in new records will be even greater.”

“Statistics alone cannot tell us what the cause of any single heat wave is, but they show a large and systematic increase in the number of heat records due to global warming,” says Stefan Rahmstorf, a co-author of the study and co-chair of PIK’s research domain Earth System Analysis. “Today, this increase is already so large that by far most monthly heat records are due to climate change. The science is clear that only a small fraction would have occurred naturally.”

Article: Coumou, D., Robinson, A., Rahmstorf, S. (2013): Global increase in record-breaking monthly-mean temperatures. Climatic Change (online) [doi:10.1007/s10584-012-0668-1]
Weblink to the article: http://link.springer.com/article/10.1007/s10584-012-0668-1

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E-Mail: press@pik-potsdam.de

50 degrees Celsius in Australia

From UNFCCC's Facebook Status


Extreme heat in Australia: The country's Bureau of Meteorology's interactive weather forecasting chart has added new colours – deep purple and pink – to extend its previous temperature range that had been capped at 50 degrees.

Climate Change Now Blamed for Volcanic Eruptions

By Laura Sinpetru

Source: Softpedia at http://news.softpedia.com/news/Climate-Change-Now-Blamed-for-Volcanic-Eruptions-317436.shtml

Up until recently, it was believed that the volcano-climate relationship only went one way. Thus, most people agree that, once a volcano erupts and releases significant amounts of sulfur dioxide into the air, the weather is bound to cool down to a certain extent.

This phenomenon happens because of a very simple reason: sunlight has a tougher time reaching the earth, Oil Price explains.

However, a new study carried out by geologists working with the GEOMAR Helmholtz Centre for Ocean Research in Kiel argues that shifts in global weather conditions can also influence the way in which active volcanoes across the world behave.

In other words, global warming can foster volcanic eruptions.

The scientists who looked into this issue explain the situation as follows: during an ice age, most of the water housed in seas and oceans turns into ice and builds up on land.

This basically means that the continents find themselves compressed by all the extra weight now sitting on top of them.

However, once this period of extreme cold comes to an end and the ice starts to melt, said extra weight makes its way back into seas and oceans.

As a result of these climate shifts' toying with the pressure applied on the continents' surface and on the sea floor on a regular basis, the magma gets agitated and sooner or later volcanic eruptions start taking place.

Although this study focused on the Pacific Ring of Fire and its responses to an ice age's settling in or coming to an end throughout the past million years, there are other scientists who argue that man-made global warming might also translate into volcanoes' erupting ever more frequently, primarily due to the melting of the Arctic ice and rising sea levels.

The findings of this study linking climate change to volcanic eruptions were published in the scientific journal Geology.