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 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.

Scientists say it is further evidence that modern-day global warming isn’t natural, but the result of rising carbon dioxide emissions that have rapidly grown since the Industrial Revolution began roughly 250 years ago.