PLEA Network

23 January 2016, Carbon Brief, Arctic and Med face hotspot worries. Uneven heating of the Earth’s surface as a result of climate change could see some regions facing seriously high rises in average temperatures. Forget the notion of a 2˚C global average temperature rise. In parts of the Arctic, regional average warming passed that limit 15 years ago. New research suggests that if the world really does warm to an average of 2˚C, then mean temperatures in the Mediterranean region could be 3.4˚C warmer than in pre-industrial times. And in some parts of the Arctic, 2˚C average warmingcould translate as a 6˚C rise. Sonia Seneviratne, head of the land-climate dynamics group at Switzerland’sInstitute for Atmospheric and Climate Science (ETH Zurich), and colleaguesreport in Nature journal that they have been thinking about the meaning of a 2˚C global average warming. Because it is an average, some regions will inevitably be hotter than this average. So she and her fellow researchers have been trying to calculate what further emissions of greenhouse gases in the atmosphere – the exhausts from fossil fuel combustion that drive global warming – will mean for the people who live in specific parts of the planet. Average warming They focused on what climate models could tell them about extremes of temperature and precipitation in selected regions on the global map. The answer is disconcerting: to limit average temperature rises for the Mediterranean to 2˚C, the world will have to sharply reduce its fossil fuel combustion and contain the global average warming to 1.4˚C. Since the planet is already on average 1˚C warmer than it was in pre-industrial times, this puts the challenge of climate change in an ever more urgent context. Professor Seneviratne pointed out two years ago that extremes might be more significant in climate change than global averages.” We could potentially see even greater regional variation than these findings show” And she is not the only researcher to look for the significance of local climate change implicit in a shift in planetary averages. A team of oceanographers in 2013 examined much the same pattern of variation and predicted that, for some regions,real and enduring climate change could arrive by 2020. Read More here