SOURCE: phys.org

DATE: February 23, 2016

AUTHOR: Marlowe Hood

SNIP: The window of opportunity for humanity to cap global warming by slashing greenhouse gases is closing faster than previously thought, according to a study released Tuesday.

Earlier estimates of our “carbon budget”—the amount of heat-trapping carbon dioxide we can still put into the atmosphere without warming Earth by more than two degrees Celsius (3.6 degrees Fahrenheit)—have ranged from 590 billion to 2.4 trillion tonnes.

The new research says the upper limit is actually half that, some 1.24 trillion tonnes of CO2.