Research NewsClimate Change

Ice Bubbles Confirm Big Chill

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Science  14 Jun 1996:
Vol. 272, Issue 5268, pp. 1584-1585
DOI: 10.1126/science.272.5268.1584


Clues in Greenland's ice sheet have shown that during the last ice age its climate repeatedly warmed sharply, only to slide into a renewed chill lasting thousands of years. Just how drastic the warmings and coolings were and how widely they were felt has been a matter of debate, but new indicators derived not from the ice itself but from trapped bubbles of ancient gases—nitrogen and methane—have confirmed the severity of the last of these climate swings. Known as the Younger Dryas, this cold snap 12,000 years ago brought temperatures 14 degrees Celsius colder than today to Greenland, and it affected much of the world.