Climate science: Bad news gets worse

Diplomats from 197 nations wound down a two-week UN conference Friday which started drafting a blueprint for arresting global warming "well below" two degrees Celsius (3.6 Fahrenheit) over pre-industrial levels. For the first time ever, the average temperature in 2015 was a full degree Celsius above the pre-industrial era benchmark used by the UN climate science panel. The atmospheric concentration of the three most potent greenhouse gases -- carbon dioxide (CO2), methane (CH4), and nitrous oxid