Tuesday, September 04, 2007

"Times Atlas shows how global warming is changing the world"

From the timesonline.co.uk

Maps are having to be redrawn as global warming and man’s use of rivers alter the shape of countries and continents around the world.

More changes than ever before are being recorded by cartographers as they attempt to keep track of the impact people have on the environment.

In the four years since the last edition of The Times Comprehensive Atlas of the World map-makers have had to redraw coastlines, lakes and the routes of rivers.

Construction of new homes and industrial plants is also having a visible effect on the world as towns and cities expand to concrete over the countryside.

Las Vegas in the United States has undergone striking changes and urbanisation in Africa and Asia is advancing rapidly. Next year is forecast to be the first in history in which more people live in urban areas than in the country.

Inland lakes and seas have seen some of the biggest changes as water from rivers is diverted to feed crops and urban populations.


Satellite images of the Aral Sea in 1973 (left) and 2004
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Lake Chad in Africa has shrunk 95 per cent since 1967 and the Aral Sea in Central Asia has contracted by 75 per cent in 40 years. Similarly, the Dead Sea is 82 feet (25 metres) lower today than it was 50 years ago.

So much water is extracted from the Yellow River in China that it can dry out so much in the summer that it fails to reach the sea, a situation exacerbated by global warming. Sediment levels have changed so radically that it has changed the shape of the coastline where the river meets the sea.

In Bangladesh the effects of climate change, which is said to have contributed to sea level rises and caused heavier monsoons, have eaten away at the low-lying coast.

“We can literally see environmental disasters unfolding before our eyes,” said Mick Ashworth, editor-in-chief of the atlas.

He said many of the revisions to the 12th edition of the atlas, published today by Collins, are a result of cartographers being “more aware of large scale environmental changes”, including global warming.

“It’s a question of keeping on top of the changes,” he said. “Awareness of the changes is definitely increasing.”

While many of the current revisions are a result of better information about what has taken place, cartographers expect atlases in the future to require considerable changes from sea level rises caused by global warming.

In the Pacific Ocean the Marshall Islands, Tokelau, Tuvalu and Vauata are among the areas of land expected to vanish as sea levels rise, as are the Maldives in the Indian Ocean.

A new feature of the atlas is the identification of ghost towns, which are marked on the maps as “abandoned”.

Among these are Plymouth in Montserrat, which was abandoned because of volcanic eruptions from 1995-7. Others are Bodie in the US, one of the Californian goldrush settlements, and Kolmanskop in Namibia, a diamond mining town.

Cartographers are keeping a close on on Shishmaref in Alaska because it is forecast to become the first US settlement abandoned because of the impacts of climate change. The break-up of sea ice has left the village more exposed to storms and the sea is advancing at a rate of ten feet (3m) a year.

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