Recent heat spike unlike anything in 11,000 years

Man trying to stay cool during heat wave

A man relaxes on a bench in the along during warm weather on July 6, 2012 in New York City. Much of the midwest experienced a severe heat wave which devastated crops and kept people indoors.(Photo by Spencer Platt/Getty Images)

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Posted: 03/07/2013

By: SETH BORENSTEIN, AP Science Writer

WASHINGTON - A new study looking at 11,000 years of climate temperatures shows the world in the middle of a dramatic U-turn, lurching from near-record cooling to a heat spike.

Research released Thursday in the journal Science uses fossils of tiny organisms to reconstruct global temperatures back to the end of the last ice age. It shows how the globe for several thousands of years was cooling until a dramatic spike in the 20th century.

Study author Shaun Marcott says his data shows that 1900 to 1910 was one of the coolest in the past 11,300 years. Yet 100 years later, the decade was one of the warmest.

Marcott and other scientists say the long-term context indicates global warming isn't natural but man-made since the start of the Industrial Revolution.