Present Global Warming Conditions Caused Ocean Levels To Rise By 40 Feet In The Past

The past has allowed researchers to foresee a probable future course for Earth, if global warming continues unabated.

 A new research published in the journal Science claims that warming levels being witnessed in the present day caused water levels to climb by at least 20 feet over current sea levels, during several periods in the past. About 125,000 years ago water level rose 20 to 30 feet when global temperatures increased one degree Celsius over preindustrial -era temperatures. The rise was perpetuated by melting of polar ice sheets in Greenland and Antarctica.

"As the planet warms, the poles warm even faster, raising important questions about how ice sheets in Greenland and Antarctica will respond," she said. "While this amount of sea-level rise will not happen overnight, it is sobering to realize how sensitive the polar ice sheets are to temperatures that we are on path to reach within decades," said study's lead author Andrea Dutton.

Dutton and her team also noted that current atmospheric carbon dioxide levels of 400 parts per million (ppm) is much higher than 280 ppm about 3 million years ago when water level rose by about 40 feet.

"This evidence leads us to conclude that the polar ice sheets are out of equilibrium with the present climate," Dutton said.

Researchers called for more studies to determine the rate of ice sheet retreat concomitant with water level rise to develop improved plans and mitigate ocean level rise.