Global warming not just about heat - SETH BORENSTEIN

The world is not just getting hotter from man-made global warming, it is getting stickier. It really is the humidity.

The amount of moisture in the air near the surface – the stuff that makes hot weather unbearable – has increased 2.2 per cent in just under three decades. And computer models show that the only explanation is man-made global warming, according to a study published in Thursday's journal Nature.

“This humidity change is an important contribution to heat stress in humans as a result of global warming,” said Nathan Gillett of the University of East Anglia in the United Kingdom, a co-author of the study.