"Our common future" in the blue planet

July 10 2015, Paris: "Emissions of carbon dioxide and other heat-trapping gases must eventually fall to zero to stabilize the global climate, according to scientists leading the biggest international climate science conference prior to the Paris UN COP meeting in December. But they also indicate cautious optimism that growing political momentum means the two degree Celsius climate upper limit is still within reach.  In practice, limiting global warming to 2 degrees Celsius above pre industrial levels will require cutting emissions of heat-trapping gases by 40-70% below current levels by 2050."