27 Sep 2013:
IPCC Scientists Warn
Of Upper Limit on CO2 Emissions
Saying it is 95 percent certain that humans have caused most of the global warming of the last half-century, scientists with the Intergovernmental Panel on Climate Change (IPCC) warned today that the world can afford to burn about 1 trillion tons of carbon
before facing extreme climate change. The IPCC’s working group on the physical sciences for the first time set an upper limit on CO2 emissions, contending that humanity can combust only one-third of the 3 trillion tons of fossil fuels that still remain in the ground. If carbon emissions continue at their current pace, IPCC scientists forecast that the trillionth ton of carbon will be released around 2040, and beyond that the world will face potentially destabilizing temperature increases exceeding 2 degrees C, or 3.6 degrees F. The physical sciences report,
compiled by hundreds of scientists and released in Stockholm, marked the first time that the IPCC had forecast that sea levels could rise by as much as three feet this century. The physical sciences report is the first of several to be released in the next year in advance of the 2014 publication of the IPCC’s fifth report on global climate change. “Human influence has been detected in warming of the atmosphere and ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes,” the Stockholm report said, warning that these effects will intensify without major efforts to curb greenhouse gas emissions.