Britain's Prince Charles (R) is greeted by Executive Secretary of the U.N. Framework Convention on Climate Change Christiana Figueres at the United Nation's 21st climate change conference at Le Bourget near Paris on November 30, 2015. The almost 150 heads of state and representatives from 200 countries in attendance will attempt to negotiate a legally binding agreement to limit worldwide carbon emissions with the goal of keeping global warming under 2 degrees Celsius.   Photo by David Silpa/UPI