Category: News

Scientists aboard a research ship that has sailed the entire length of Russia’s northern coast have discovered intense concentrations of methane – sometimes at up to 100 times background levels – over several areas covering thousands of square miles of the Siberian continental shelf.

In the past few days, the researchers have seen areas of sea foaming with gas bubbling up through “methane chimneys” rising from the sea floor. They believe that the sub-sea layer of permafrost, which has acted like a “lid” to prevent the gas from escaping, has melted away to allow methane to rise from underground deposits formed before the last ice age.

They have warned that this is likely to be linked with the rapid warming that the region has experienced in recent years.

Methane is about 20 times more powerful as a greenhouse gas than carbon dioxide and many scientists fear that its release could accelerate global warming in a giant positive feedback where more atmospheric methane causes higher temperatures, leading to further permafrost melting and the release of yet more methane.

The amount of methane stored beneath the Arctic is calculated to be greater than the total amount of carbon locked up in global coal reserves so there is intense interest in the stability of these deposits as the region warms at a faster rate than other places on earth.

Orjan Gustafsson of Stockholm University in Sweden, one of the leaders of the expedition, described the scale of the methane emissions in an email exchange sent from the Russian research ship Jacob Smirnitskyi.

“We had a hectic finishing of the sampling programme yesterday and this past night,” said Dr Gustafsson. “An extensive area of intense methane release was found. At earlier sites we had found elevated levels of dissolved methane. Yesterday, for the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface. These ‘methane chimneys’ were documented on echo sounder and with seismic [instruments].”

At some locations, methane concentrations reached 100 times background levels. These anomalies have been seen in the East Siberian Sea and the Laptev Sea, covering several tens of thousands of square kilometres, amounting to millions of tons of methane, said Dr Gustafsson. “This may be of the same magnitude as presently estimated from the global ocean,” he said. “Nobody knows how many more such areas exist on the extensive East Siberian continental shelves.

“The conventional thought has been that the permafrost ‘lid’ on the sub-sea sediments on the Siberian shelf should cap and hold the massive reservoirs of shallow methane deposits in place. The growing evidence for release of methane in this inaccessible region may suggest that the permafrost lid is starting to get perforated and thus leak methane… The permafrost now has small holes. We have found elevated levels of methane above the water surface and even more in the water just below. It is obvious that the source is the seabed.”

The preliminary findings of the International Siberian Shelf Study 2008, being prepared for publication by the American Geophysical Union, are being overseen by Igor Semiletov of the Far-Eastern branch of the Russian Academy of Sciences. Since 1994, he has led about 10 expeditions in the Laptev Sea but during the 1990s he did not detect any elevated levels of methane. However, since 2003 he reported a rising number of methane “hotspots”, which have now been confirmed using more sensitive instruments on board the Jacob Smirnitskyi.

Dr Semiletov has suggested several possible reasons why methane is now being released from the Arctic, including the rising volume of relatively warmer water being discharged from Siberia’s rivers due to the melting of the permafrost on the land.

The Arctic region as a whole has seen a 4C rise in average temperatures over recent decades and a dramatic decline in the area of the Arctic Ocean covered by summer sea ice. Many scientists fear that the loss of sea ice could accelerate the warming trend because open ocean soaks up more heat from the sun than the reflective surface of an ice-covered sea.

That’s an amount that exceeds the most dire outlook for emissions from burning coal and oil and related activities as projected by a Nobel Prize-winning group of international scientists in 2007.

Meanwhile, forests and oceans, which suck up carbon dioxide, are doing so at lower rates than in the 20th century, scientists said. If those trends continue, it puts the world on track for the highest predicted rises in temperature and sea level.

The pollution leader was China, followed by the United States, which past data show is the leader in emissions per person in carbon dioxide output. And while several developed countries slightly cut their CO2 output in 2007, the United States churned out more.

Still, it was large increases in China, India and other developing countries that spurred the growth of carbon dioxide pollution to a record high of 9.34 billion tons of carbon (8.47 billion metric tons). Figures released by science agencies in the United States, Great Britain and Australia show that China’s added emissions accounted for more than half of the worldwide increase. China passed the United States as the No. 1 carbon dioxide polluter in 2006.

Emissions in the United States rose nearly 2 per cent in 2007, after declining the previous year. The U.S. produced 1.75 billion tons of carbon (1.58 billion metric tons).

“Things are happening very, very fast,” said Corinne Le Quere, professor of environmental sciences at the University of East Anglia and the British Antarctic Survey. “It’s scary.”

Gregg Marland, a senior staff scientist at the U.S. Department of Energy’s Oak Ridge National Laboratory, said he was surprised at the results because he thought world emissions would drop because of the economic downturn. That didn’t happen.

“If we’re going to do something (about reducing emissions), it’s got to be different than what we’re doing,” he said.

China the trendsetter

The emissions are based on data from oil giant BP PLC, which show that China has become the major driver of world trends. China emitted 2 billion tons of carbon (1.8 billion metric tons) last year, up 7.5 per cent from the previous year.

“We’re shipping jobs offshore from the U.S., but we’re also shipping carbon dioxide emissions with them,” Marland said. “China is making fertilizer and cement and steel and all of those are heavy energy-intensive industries.”

Developing countries not asked to reduce greenhouse gases by the 1997 Kyoto treaty — and China and India are among them — now account for 53 percent of carbon dioxide pollution. That group of nations surpassed industrialized ones in carbon dioxide emissions in 2005, a new analysis of older figures shows.

India is in position to beat Russia for the No. 3 carbon dioxide polluter behind the United States, Marland said. Indonesia levels are increasing rapidly.

Denmark’s emissions dropped 8 percent. The United Kingdom and Germany reduced carbon dioxide pollution by 3 percent, while France and Australia cut it by 2 per cent.

Nature can’t keep up with the carbon dioxide from man, Le Quere said. She said from 1955 to 2000, the forests and oceans absorbed about 57 per cent of the excess carbon dioxide, but now it’s 54 per cent.

What is “kind of scary” is that the worldwide emissions growth is beyond the highest growth in fossil fuel predicted just two years ago by the Intergovernmental Panel on Climate Change, said Ben Santer, an atmospheric scientist at the Lawrence Livermore National Lab.

Under the panel’s scenario then, temperatures would increase by somewhere between 4 and 11 degrees Fahrenheit (2.4 to 6.3 degrees Celsius) by the year 2100.

If this trend continues for the century, “you’d have to be luckier than hell for it just to be bad, as opposed to catastrophic,” said Stanford University climate scientist Stephen Schneider.