Extreme heat becoming more frequent and intense, UN agency says

Periods of extreme heat are becoming more frequent, intense and longer-lasting as climate change warms the planet, the UN weather agency said on Tuesday, noting changes since the famously hot European summer of 1976.

GENEVA, Aug 11 - Periods of extreme heat are becoming more frequent, intense and longer-lasting as climate change warms the planet, the U.N. weather agency said on Tuesday, noting changes since the famously hot European summer of 1976.