Greenhouse Gases Hit New High, Rise Accelerates

Published on Friday, February 16, 2007 by Reuters

by Alister Doyle

OSLO - Greenhouse gases widely blamed for causing global warming have jumped to record highs in the atmosphere, apparently stoked by rising emissions from Asian industry, a researcher said on Friday.

"Levels are at a new high," said Kim Holmen, research director of the Norwegian Polar Institute which oversees the Zeppelin measuring station on the Arctic archipelago of Svalbard about 1,200 km (750 miles) from the North Pole.

He told Reuters that concentrations of carbon dioxide, the main greenhouse gas emitted largely by burning fossil fuels in power plants, factories and cars, had risen to 390 parts per million (ppm) from 388 a year ago.

Levels have hit peaks almost every year in recent decades, bolstering theories of warming, and are far above 270 ppm before the Industrial Revolution of the 18th century. Climate scientists say the heat-trapping gas is blanketing the planet.

Holmen said the increase of 2 ppm from 2006 reflected an accelerating rise in recent years. "When I was young, scientists were talking about 1 ppm rise" every year, he said. "Since 2000 it has been a very rapid rate."

"The large increases in release rates are definitely in the Asian economies," led by China, he said. China is opening coal-fired power plants at the rate of almost one a week.

SPRING FALL

Carbon dioxide concentrations peak just before the northern hemisphere spring, when plants start soaking up the gas as they grow. Southern hemisphere seasons have less effect since there are fewer land masses -- and plants -- south of the equator.

The Zeppelin station is run in cooperation with Stockholm University and is one of the main measuring points along with a station in Hawaii. Remoteness from industrial centers helps.

Scientists say the concentration of carbon dioxide, according to the modern records, is at its highest in the atmosphere in at least 650,000 years.

The world's top climate scientists said in a report on February 2 they were more than 90 percent certain that human activities, led by burning fossil fuels, were to blame for warming. That was up from 66 percent certainty in a previous report in 2001.

The U.N.'s Intergovernmental Panel on Climate Change said that temperature rises were set to accelerate and could gain by between 1.1 and 6.4 Celsius (2.0-11.5 Fahrenheit) by 2100, bringing more floods, droughts and rising sea levels.

Apart from human emissions from burning fossil fuels, he said there were other factors that could affect carbon dioxide levels in future.

On the one hand, plants may grow more in a warmer world, soaking up more carbon dioxide. But if the soil gets warmer, dead plants and leaves may rot more in winter, releasing more carbon.

Any heating of the oceans may means less absorption of carbon dioxide, partly because the greater buoyancy of warmer water inhibits a mixing with deeper lev