Monday, January 9, 2012

Is Another Ice Age Imminent?

Throughout the history of the planet, the world periodically experienced ice ages when most of the earth was covered in ice sheets and glaciers. They advance and retreat rhythmically on the earth’s surface. Scientists believe that the immediate past ice age ended just 11000 years ago. Many of them believe that it is time for the polar ice to advance towards the equator. May be global warming due to the pumping of greenhouse gases in the last few centuries has temporarily halted the rapid advance of ice sheets.
The ice advance is called glacial, and the warm period in between interglacial. In the past, the interglacial period lasted for around 11,000 years. The current interglacial has already lasted 11,000 years and it might end at any time. Some scientists think, as mentioned, that fuel burning has held the ice advance and some others think that it might trigger another ice age.  Anyway, we have already passed the normal interglacial and a new ice age is imminent, irrespective of this ‘triggering’. During this period, the cold, dry air above the Arctic and Antarctica carries little moisture and drops little snow there. An increase in global temperature could increase the amount of moisture in the air and thus increase the amount of snowfall. After years of more snowfall, the Polar Regions could accumulate more ice. These ice sheets will reflect more sunlight that falls on the earth making it cooler and thus helping the ice to advance.   
Unlike the movie, “The day after tomorrow”,  the next ice age will not happen in a matter of days, but most likely in a few decades. It may not start during our lifetimes. During the ice ages, almost all forms of life will find survival more difficult than during the warm periods like the one we experience now. We will run out of supplies and need to start living off the land as cultivation would become hard as humans will have to shift towards the equator. Food, shelter, water and clothing will be harder to procure. Those who live in the north latitudes will have to shift southward and there will be too much crowding near the equator which is already overpopulated. How many will survive? How hard will be our survival?  We have to wait and see.  

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