Global temperature may be rising

Press, 8 March 1984, Page 22

Global temperature may be rising

NZPA-Reuter Washington

The astronomer, Dr Carl Sagan, called for an international forum to tackle the “greenhouse effect,” the gradual rise in the world’s temperature caused by burning coal and oil and by clearing forests.

“We are pushing and pulling on the world’s environment ... in ways we don’t understand and in ways which may have serious consequences,” Dr Sagan told a joint hearing of two Congressional science and technology subcommittees. Dr Sagan, a member of Cornell University’s radiophysics and space research department, said the greenhouse effect was a global problem which the United States alone could not solve.

“It is my view that the way to deal with this problem is in some large international forum,” he said. Most scientists agree that higher carbon dioxide levels in the atmosphere caused by destroying vegetation and burning fossil fuels are gradually warming the global climate.

The temperature rise could turn fertile land into desert and melt the polar ice pack, raising the sea level and flooding coastal plains. By the end of the twentyfirst century, carbon dioxide content in the atmosphere is expected to reach more than twice the level it was before the industrial age.

“There is a consensus that in doubling the atmosphere’s CO2 content we will warm the planet’s surface somewhere between

2deg. and sdeg. Celsius,” said Dr Wallace Broecker, professor of geological sciences at New York’s Columbia University. Professor Broecker said researchers estimated that during the ice age of 20,000 years ago, the Earth’s temperature was only 4deg. to sdeg. Celsius lower that it is now.

This suggested that a similar rise in temperature would produce major environmental changes which could come in sizeable jumps and hit with little warning, he said. Professor Broecker called for a “bold new national effort” aimed at gaining a better understanding of the atmosphere, oceans, ice, and the Earth’s biosphere. He said the quantity of gases such as methane, freon, and nitrous oxide in

the atmosphere, which share carbon dioxide’s capacity to warm the planet, was also rising, possibly speeding up the warming process. Rafe Pomerance, president of the environmental organisation. Friends of the Earth, called for immediate steps to forestall drastic climatic change, which he called the most serious environmental risk next to nuclear war.

“The latest evidence indicates that we are locked into a Ideg. Celsius global warming if we never burned another gallon of oil or another tonne of coal,” he said.

He said the United States could help prevent more serious warming through energy conservation and expanded research into alternative energy sources.