Antarctic icecaps could help scientists predict Earth's future weather

Former U.S. Vice President Al Gore is silhouetted against an image of the earth during a climate change talk in Manila. File Photo

London’s Science Museum will feature three pieces of ice core, drilled from the Antarctic icecap, which could help scientists predict Earth’s future weather.

They will be installed in a glass-fronted freezer cabinet in the Science Museum in London’s new Atmosphere gallery.

“This gallery will show how scientists have acquired their knowledge about Earth’s climate history -- with our ice cores providing some of the most telling examples,” the Observer quoted museum director Chris Rapley, as saying.

Air gets trapped by snow as it falls. Then more snow falls on top. Pressure builds up and snow is eventually converted into ice -- with air bubbles trapped inside. The deeper you drill, the older the ice -- and air bubbles -- that you find.

“If you drill several kilometres down you find samples that are almost a million years old. That is why we think of ice cores as treasure troves of climate history,” Rapley said.

By drilling down to a particular layer, the oxygen isotopes in a core sample’s air bubbles reveal the global temperature for the time that the air was trapped in snowflakes.

This temperature can then be compared with the air’s carbon dioxide content. Similarly, salt and dust contamination provides information about sea levels and the spread of deserts across the globe at any given time over the last 800,000 years.

“The one critical feature we get from these measurements is that the temperature of Earth’s atmosphere and its carbon dioxide content are locked together in a coupled system,” said Rapley.

“If one of those variables increases, the other will also rise. Hence the worry about the amounts of carbon dioxide we pump into the atmosphere. If unchecked, these could lead to global temperature rises of up to six degrees Celsius by the end of the century.”