Voice of America: A leading U.S. advocate for combating climate change has unveiled an ambitious plan to drastically slash global carbon emissions over the next 12 years, saying aggressive action is both necessary and feasible. VOA’s Michael Bowman reports from Washington. Both major U.S. presidential candidates say they are committed to putting the United States on a path to cut emissions of carbon dioxide and other so-called “greenhouse gases” by 60 to 80 percent by the year 2050. …