Environmental News Network: Politically contentious as ever, climate change is back in the headlines, as a brutal, deep and prolonged southward shift in the polar vortex has put much of the continental U.S. in a deep freeze. In stark contrast, people living in the Southern Hemisphere in Australia, Argentina and Brazil, for example are trying to cope with heat waves, the threat of drought and power outages in major cities. While many are scrambling with the immediacy of such problems, the U.S. Environmental Protection Agency...