Global warming: Fast Arctic thaw

Fast Arctic thaw threatens people, polar bears

Global warming is heating the Arctic almost twice as fast as the rest of the planet in a thaw that threatens the livelihoods of millions of people and could wipe out polar bears by 2100, according to an eight-nation report released on Monday.

The report, the work of more than 250 scientists and the biggest survey to date of the Arctic climate, found that the accelerating melt could point to wider disruptions from a build-up of human emissions of heat-trapping gases in the earth?s atmosphere.

The ?Arctic climate is now warming rapidly and much larger changes are projected,? according to the Arctic Climate Impact Assessment (ACIA), which was commissioned by the Arctic Council and funded by the United States, Canada, Russia, Denmark, Iceland, Sweden, Norway and Finland.

The report projects that temperatures in the Arctic will rise by 8 to 14 degrees Fahrenheit in the next 100 years. If temperatures then stayed stable, the Greenland icecap would melt altogether in 1,000 years and raise global sea levels by about 23 feet.

Possible benefits like more productive fisheries, easier access to oil and gas deposits or trans-Arctic shipping routes would be outweighed by threats to indigenous peoples and the habitats of animals and plants.

Sea ice around the North Pole, for instance, could almost disappear in summer by the end of the century, it said. The extent of the ice has already shrunk by 15-20 percent in the past 30 years.

?Polar bears are unlikely to survive as a species if there is an almost complete loss of summer sea-ice cover,? the report said. On land, creatures like lemmings, caribou, reindeer or snowy owls are being forced north into a narrower range.

Fossil fuels blamed
The report mainly blames the melt on gases from fossil fuels burnt in cars, factories and power plants. The Arctic warms faster than the global average because dark ground and water, once exposed, traps more heat than reflective snow and ice.

?Changes in the Arctic provide an early indication of the environmental and societal significance of global warming,? it said.

The thaw will have a global impact ? melting of glaciers will raise global sea levels by about 4 inches by the end of the century.

Many of the four million people in the Arctic are already affected. Buildings from Russia to Canada have been demolished because of subsidence linked to thawing permafrost that also destabilizes oil pipelines, roads and airports.

FACT FILE What drives climate change?
? Solar input
? The atmosphere
? The oceans
? The water cycle
? Clouds
? Ice and snow
? Land surfaces
? Human influences

Solar input
A third of the sun's energy is reflected back into space after hitting Earth's upper atmosphere, but two thirds gets through, driving Earth's weather engine.
The atmosphere
A delicate balance of gases gives Earth its livable temperature. Known as "greenhouse" gases because they trap heat inside the atmosphere, they send a portion of that heat back to Earth's surface. The gases include water vapor, carbon dioxide, methane and nitrous oxide.
The oceans
Covering two thirds of Earth, oceans are the key source of moisture in the air and they store heat efficiently, transporting it thousands of miles. The oceans and marine life also consume huge amounts of carbon dioxide.
The water cycle
Higher air temperatures can increase water evaporation and melting of ice. And while water vapor is the most potent greenhouse gas, clouds also affect evaporation, creating a cooling effect.
Clouds
They both cool Earth by reflecting solar energy and warm Earth by trapping heat being radiated up from the surface.
Ice and snow
The whiteness of ice and snow reflects heat out, cooling the planet. When ice melts into the sea, that drives heat from the ocean.
Land surfaces
Mountain ranges can block clouds, creating "dry" shadows downwind. Sloping land allows more water runoff, leaving the land and air drier. A tropical forest will soak up carbon dioxide, but once cleared for cattle ranching, the same land becomes a source of methane, a greenhouse gas.
Human influences
Humans might be magnifying warming by adding to the greenhouse gases naturally present in the atmosphere. Fuel use is the chief cause of rising carbon dioxide levels. On the other hand, humans create temporary, localized cooling effects through the use of aerosols, such as smoke and sulfates from industry, which reflect sunlight away from Earth.


Indigenous hunters are falling through thinning ice and say that prey from seals to whales is harder to find. Rising levels of ultra-violet radiation may cause cancers.

Changes under way in the Arctic ?present serious challenges to human health and food security, and possibly even (to) the survival of some cultures,? the report says.

Even so, farming could benefit in some areas, while more productive forests are moving north onto former tundra.

Scientists will meet in Iceland this week to discuss the report. Foreign ministers from Arctic nations are due to meet in Iceland on Nov. 24 but diplomats say they are deeply split with Washington least willing to make drastic action.

'Sidetrack' strategy?
Some European partners have accused the Bush administration of trying to weaken the report.

President Bush has made clear he opposes mandatory curbs on gases like carbon dioxide, which create a greenhouse effect on Earth. Many scientists fear fossil fuel sources of CO2 and other gases are warming the Earth beyond the natural greenhouse effect.

Bush also pulled out of the U.N.?s 1997 protocol on global warming, arguing it was too expensive and exempted China, India and other rapidly developing nations.

Most other industrial nations, most recently Russia, have agreed to Kyoto?s target of cutting developed nations? CO2 emissions by five percent below 1990 levels by 2008-12.


How the Earth maintains a temperature conducive to life
One European negotiator said the administration is trying to "sidetrack the whole process so it is not confronted with the question, 'Do you believe in climate change, or don't you?'"

A European diplomat added that ?U.S. negotiators say 'we already have a policy on global warming ? we can?t have a new one just for the Arctic'."

The negotiator added that while the other member nations will try to press the United States on the matter in the final talks, "I cannot see any solution to this unless (the Bush administration) clearly changes its position."

Scientists agreed to discuss parts of the Arctic Council report ahead of full publication. And some European governments originally wanted the report issued before Tuesday?s U.S. presidential election.

U.S. objection to wording
The Washington Post reported on Oct. 4 reported that the Bush administration has lobbied to drop a policy section stating that in order to meet climate goals set in 1992, the "Arctic Council urges the member states to individually and when appropriate, jointly, adopt climate change strategies across relevant sectors. These strategies should aim at the reduction of the emission of greenhouse gases."

A senior State Department official who asked not to be identified told the Post that "we're bound by the administration's position. We're not going to make global climate policy at the Arctic Council."

Environmental groups have urged the council to crack down.

?The big melt has begun,? Jennifer Morgan, director of the World Wildlife Fund?s global climate change campaign, said in a statement. She said industrialized nations were using the Arctic as a guinea pig in an uncontrolled experiment on climate change.