Planet melting

If global warming continues, polar ice caps will melt, wiping nations off our planet

Published: Sunday 31 January 1999

 Ice caps: on the verge of a m (Credit: bradley p robinson)now that everyone -- world leaders, scientists and the masses -- have accepted global warming as reality and not just some crazy theory cooked up by zealous environmentalists, facts regarding its effects are pouring in.

us scientists recently observed that the Quelccaya ice cap in the South American Andes -- the hemisphere's largest glacier -- is melting. "Where it was shrinking by three metres a year earlier, it is receding by as much as 30 metres now," says Ellen Mosley Thompson, glacier expert and professor at the Ohio State University. Dozens of ancient glaciers from Andes to Montana's Lewis Range in the us have turned to slush as global temperatures soared in the past decade. The facts are alarming: half the glacier ice in the European Alps has disappeared over the past 100 years; the southern tip of Argentina in Antarctica has warmed up by 2.5 o c since the mid-1940s, and Antarctica has never been so hot according to a research team of the us Geological Survey. The once-frozen continent is experiencing its hottest temperatures in over 4,000 years. Then in October 1998, an iceberg 7,125 sq km in area separated from the Ronnie ice shelf, the second-largest ice cap in Antarctica. The British Antarctic Survey warned that if Ronnie melts, sea levels would go up by at least five metres, inundating coastal regions.

The Arctic ice, too, is now a third thinner than it was in 1976, claim two studies conducted by Peter Wadhams, reader in polar studies at the Scott Polar Institute ( spi ) in Cambridge, uk , and Norman Davis, senior research fellow, also from spi . Back in the 1970s, the average thickness of Arctic ice used to be some six metres. Now, it is down to just four. The reason for this dramatic thinning? Carbon dioxide ( co 2 ) and other greenhouse gases in the atmosphere.

Polar regions are highly sensitive, and any temperature changes could be up to five times as large as those at the tropics. This is because of a mechanism known as the 'ice-albedo feedback mechanism', in which white sea-ice keeps the polar regions cool by reflecting the sunlight. If the ice melts, it will expose the dark sea waters, absorb more sunlight and cause further melting. And the effects could be disastrous. The massive rush of water could drown almost one-third of Bangladesh and wipe Maldives off the world map.

When the Greenland sea-ice freezes in winter, a built-up of salty water sinks to the bottom carrying huge amounts of dissolved co 2 from the atmosphere with it. Slowing down of this peculiar phenomenon could lead to accumulation of co 2 , thus speeding up global warming.

Humans are now paying the price for damaging the planet by adding billions of tonnes of co 2 and numerous other greenhouse gases to the atmosphere, which, in near future, could lead to world-wide calamities.

The Inter-governmental Panel on Climate Change( ipcc ) in its scientific consensus stated that global warming is partly human-induced, and global mean temperature will rise by 1 c -3.5 c in the 21st century. Thirteen of the 14 hottest years in the history of the planet have occurred since 1980, and six of the first eight months of 1998 were the warmest since 1866, with July recorded as the hottest single month ever recorded. Researchers at the University of Massachusetts, usa , say that recent temperatures are the hottest in 600 years.

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