Associated Press: The U.N.'s environmental authority has quietly raised its assessment of the level at which global greenhouse gas emissions must peak to avoid dangerous climate change, as governments seek a new accord to fight global warming.
In its first four annual emissions reports in 2010-2013, the United Nations Environment Program said emissions must not exceed 44 billion tons in 2020 for the world to limit global warming to 2 degrees C (3.6 degrees F).
But with real-world emissions rising far beyond...