WASHINGTON — A 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 marine 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 an unprecedented reversal in the 20th century.
The researchers say it is evidence that modern-day global warming is not natural but the result of rising carbon dioxide emissions that have grown since the Industrial Revolution began roughly 250 years ago.
The decade of 1900 to 1910 was one of the coolest in the past 11,300 years, the marine fossil data suggest. Yet 100 years later, the decade of 2000 to 2010 was one of the warmest, said study lead author Shaun Marcott of Oregon State University.