Reuters: Global warming’s effects this century could be twice as extreme as estimated just six years ago, scientists reported on Tuesday. Earth’s median surface temperature could rise 9.3 degrees F (5.2 degrees C) by 2100, the scientists at the Massachusetts Institute of Technology found, compared to a 2003 study that projected a median temperature increase of 4.3 degrees F (2.4 degrees C). The new study, published in the American Meteorological Society’s Journal of Climate, said the …