Earth may be too hot for humans by 2300

in

Climate change could make much of the world too hot for human habitation within just three centuries, research released Tuesday showed.
Scientists from Australia's University of New South Wales and Purdue University in the United States found that rising temperatures in some places could mean humans would be unable to adapt or survive.
http://www.independent.co.uk/environment/earth-may-be-too-hot-for-humans...
and
http://www.pnas.org/content/early/2010/04/26/0913352107.abstract?sid=ed5...