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Global warming is set to stall over the next 10 years as natural variations in ocean currents counteract manmade climate change.

Researchers modelling the climate of Europe and North America found that a major ocean current that brings warm water northwards is set to weaken, potentially offsetting temperature rises caused by human activity.

A team led by Noel Keenlyside at the Leibniz Institute for Marine Science in Germany focused on an ocean current known as the meridional overturning current or MOC. The current acts as a huge conveyor belt, bringing warm water into the North Atlantic and returning cold water to the south.

Scientists believe the ocean current strengthens and weakens on a natural cycle with a 70 to 80-year period. When the current is strong, it brings warmer water and a milder climate to northern regions.

The team’s models, which were checked against historical temperature changes, suggest the current will weaken enough to cool the North Atlantic, while temperatures in the tropical Pacific are unlikely to change.

The study appears in the journal Nature today.

“Our results show that global mean temperatures may plateau or cool weakly over the next 10 years because of natural fluctuations, but in the long term temperatures will continue to rise,” said Dr Keenlyside. “This doesn’t change the bottom line on global warming.”

Reports from the UN Intergovernmental Panel on Climate Change suggest carbon emissions could drive global temperatures up by as much as 0.2C each decade.

Put at risk by global warming, the polar bear is getting a life line as the government officially has declared it a threatened species in need of increased protection. But another round of legal battles surrounding the majestic animal may be just beginning.

The Interior Department put the bear under the protective umbrella of the Endangered Species Act on Wednesday, concluding what biologists have been saying for years: the bear is on the way to extinction because of the rapid disappearance of the Arctic sea ice upon which it depends.

Scientists predict sea ice melting will continue and even accelerate as a result of global warming.

“This in my judgment makes the polar bear a threatened species, one likely to become in danger of extinction in the foreseeable future,” said Interior Secretary Dirk Kempthorne, punctuating his point with an array of slides, charts and maps showing the changing ice flows of the Arctic.

But Kempthorne also said that he did not view the increased protection of the bear afforded by the Endangered Species Act as a back door to regulate greenhouse gases coming from power plants, automobiles and industrial sources.

“That would be a wholly inappropriate use of the ESA law,” declared Kempthorne as he outlined a series of administrative and other actions he would take to protect anything like that from happening.

The restrictions, including one that would provide the bear no more protection from oil drilling in Arctic waters than it now has under another federal law, the Marine Mammal Protection Act, prompted environmentalists and some members of Congress to questions whether the bear will get any more protection at all.

“They’re trying to make this a threatened listing in name only with no change in today’s impacts and that’s not going to fly,” said Jamie Rappaport Clark of Defenders of Wildlife and a former director of the U.S. Fish and Wildlife Service in the Clinton administration.

Three environmental groups whose lawsuit forced the Interior Department to make a decision on the bear’s status, indicated they are preparing to go to court again to challenge some of the provisions Kempthorne outlined.

These measures amount to the bear not getting all the protections it in entitled to under the Endangered Species Act and won’t hold up in court, said Kassie Siegel of the Center for Biological Diversity.

Andrew Wetzler of the Natural Resources Defense Council said the Interior Department’s decision allows loopholes in the law “to allow the greatest threat to the polar bear — global warming pollution — to continue unabated.”

Kempthorne acknowledged that the polar bear — 25,000 of them that roam the Arctic region from Russia and Alaska to Greenland — “poses a unique conservation challenge.” It is the first time in the history of the Endangered Species Act that the law has been used to protect an animal whose nemesis is global warming.

“I want to make clear that this listing will not stop global climate change or prevent any sea ice from melting,” said Kempthorne. “…The ESA is not the right tool to set U.S. climate policy.”

Kempthorne sought to assure the business community that the bear’s protection would not keep someone from building a coal-burning power plant or drill for oil in Arctic waters.

The U.S. Chamber of Commerce applauded the decision. “It will protect polar bears while also protecting American jobs and businesses,” said Bill Kovacs, the Chamber’s vice president for environmental affairs.

But some business groups weren’t as impressed.

The ruling “will unleash a torrent of lawsuits” by environmentalists and “give them a powerful new legal sledgehammer” against businesses and agricultural operations especially in the West, warned Jim Sims, president of the Western Business Roundtable.

Reed Hopper, an attorney for the Pacific Legal Foundation, which frequently has challenged the Endangered Species Act in property rights disputes, said he plans to challenge the bear listing as well in court.

The polar bear “already is the most protected (animal) in the world and needs no additional protection,” maintained Hopper. He noted the number of polar bears have more than doubled since the late 1960s from 12,000 to about 25,000 across the Arctic region from Alaska to Greenland.

Interior Department scientists in a series of reports last September that were heavily relied on by Kempthorne in his listing decision, concludes that continuing melting of sea ice will lead to a two-thirds decline in polar bears by mid-century, meaning the disappearance of at least 15,000 bears.

Via : Yahoo News

An ancient global warming episode drastically changed the planet. Life on Earth needed 200,000 years to recover. What we’re headed for in the next century could be even bigger.