AP Science Writer
KENSINGTON, Maryland (AP) — In just 50 years, 2 billion to 3.5 billion people, mostly the poor who can't afford air conditioning, will be living in a climate that historically has been too hot to handle, a new study said.
With every 1.8 degree (1 degree Celsius) increase in global average annual temperature from man-made climate change, about a billion or so people will end up in areas too warm day-in, day-out to be habitable without cooling technology, according to ecologist Marten Scheffer of Wageningen University in the Netherlands, co-author of the study.
How many people will end up at risk depends on how much heat-trapping carbon dioxide emissions are reduced and how fast the world population grows.
Under the worst-case scenarios for populatio