6 December 2015, Climate News Network, Scientists post extreme weather warning. COP21: Climate change means that temperate Europe faces the twin threat of life-threatening heatwaves and periods of bitter cold over the next 20 years. New research warns that longer, hotter and more frequent heatwaves than those that killed 55,000 Russians in 2010, or 72,000 in France, Portugal, Italy, the Netherlands, Germany and the UK in 2003, will hit Europe in the next two decades. But, over the same period, Europe could also begin to get colder as a consequence of a drop in solar activity, and a century-long chill could be on the way, according to a study of long-period climate cycles. And if global warming accelerates, and average global ocean temperatures rise by 6°C or more, most of the living, breathing world could in any case begin to suffocate, according to ominous calculations by a mathematician. At some point, the providers of oxygen could begin to perish. All three uncomfortable projections were published as 30,000 delegates, politicians, observers, pressure groups, and journalists gathered in Paris for COP21, the UN summit on climate change, which is meeting to try to forge an agreement that could, ultimately, limit global warming to a planetary average of 2°C or less. Magnitude index Simone Russo, a geophysicist, and colleagues from the European Union Joint Research Centre at Ispra in Italy report in Environmental Research Letters that they developed a heatwave magnitude index to cope with a problem once considered improbable for temperate Europe − extremes of heat. The index is a tool for statistical analysis, and provides a way of matching bygone events with possible future extremes. Deaths in Europe accounted for 90% ofglobal mortality from heat extremes in the last 20 years. And there could be more on the way. Read More here
13 November 2015, Climate News Network, Global warming drains the water of life. Melting snowpack in Turkey’s Lesser Caucasus mountains. New research warns that rising temperatures are reducing the mountain snow on which billions of people in lowland areas depend for their water supply. Up to two billion people who depend on winter snow to deliver their summer water could see shortages by 2060 as upland and mountain snowpacks continue to dwindle. An estimated 300 million people could find, 45 years on, that they simply won’t have enough water for all their needs, according to new research. Climate change driven by rising atmospheric levels of carbon dioxide – in turn, fed by human combustion of fossil fuels – may already be affecting global precipitation. Researchers have consistently found that much of the world’s drylands will increase as global average temperatures rise. But warmer temperatures increasingly also mean the water that once fell as snow, to be preserved until the summer, now falls as winter rain, and runs off directly. The snow that does fall is settling at ever higher altitudes and melting ever earlier. Reliable flow This is bad news for agricultural communities that depend on a reliable flow of meltwater every summer. California is already in the grip of a sustained drought, made worse by lower falls of snow. Great tracts of Asia depend on summer meltwater from the Himalayan massif and the Tibetan plateau. Justin Mankin, an environmental scientist at Columbia University’s Earth Institute in the US, and colleagues report in Environmental Research Letters journal that they studied 421 drainage basins across the northern hemisphere. Read More here