Global warming curbs won’t prevent steep sea rise

March 21st, 2012 - 2:07 pm ICT by IANS  

Sydney, March 21 (IANS) Even if we manage to curb global warming to two degrees Celsius, future generations could still face a sea level rise 12 to 22 metres higher than present levels, a study reveals.

A team led by Ken Miller, professor of geology from Rutgers University, US and Tim Naish professor from Victoria University of Wellington, New Zealand, studied sediment cores in Virginia in the US, Enewetak Atoll in the Pacific and the Whanganui region of New Zealand.

They investigated the late Pliocene epoch - 2.7 million to 3.2 million years ago - which is the last time the carbon dioxide level in the atmosphere was at its current level, and atmospheric temperatures were two degrees higher than they are now, the journal Geology reported.

“We know that global sea levels at this time were higher than present, but estimates have varied from five to over 40 metres higher,” said Naish, according to a university statement.

He said the team analysed the position of the sea level three million years ago and concluded that it was extremely likely - with 95 percent confidence - that sea level peaked 10 to 30 metres above present, with a best estimate of 22 metres.

“Whanganui holds one of the world’s best geological archives of global sea-level during the warm climate of the Pliocene and is a key data set in this new study,” said Naish, who has been conducting research there for the last 20 years.

Naish also led an international team to Antarctica as part of the ANDRILL Project to drill beneath the floor of the Ross Sea in 2006 and discovered that the Antarctic ice sheets retreated significantly during the Pliocene epoch.

“What we’re seeing is that the evidence of Antarctic ice sheet collapse is consistent with evidence for sea-level rise in this new study,” said Naish.

Miller, who led the study, said that sea-level rise would take time. “You don’t need to sell your beach real estate yet, because melting of these large ice sheets will take from centuries to a few thousand years,” he said.

“The current trajectory for the 21st century global rise of sea level is 2 to 3 feet (0.8 to one metre) due to warming of the oceans, partial melting of mountain glaciers, and partial melting of Greenland and Antarctica,” added Miller.

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