MACKENZIE RIVER DELTA, Northwest Territories – Pure methane, gas bubbling up from underwater vents, escaping into northern skies, adds to the global-warming gases accumulating in the atmosphere. And pure methane escaping in the massive amounts known to be locked in the Arctic permafrost and seabed would spell a climate catastrophe. Is such an unlocking under way? Researchers say air temperatures here in northwest Canada, in Siberia and elsewhere in the Arctic have risen more than 2.5 C (4.5 F) since 1970 — much faster than the global average. In 2007, air monitors detected a rise in methane concentrations in the atmosphere, apparently from far northern sources. Russian researchers in Siberia expressed alarm, warning of a potential surge in the powerful greenhouse gas, additional warming of several degrees, and unpredictable consequences for Earth's climate. The data will come from teams like one led by Scott Dallimore, who with Canadian researcher Rob Bowen and others pitched tents here on the remote, boggy fringe of North America, 2,200 kilometers (1,400 miles) from the North Pole, to learn more about seeps in the 25,000 lakes of this vast river delta. Permafrost, tundra soil frozen year-round and covering almost one-fifth of Earth's land surface, runs anywhere from 50 to 600 meters (160 to 2,000 feet) deep in this region. Entombed in that freezer is carbon — plant and animal matter accumulated through millennia. As the soil thaws, these ancient deposits finally decompose, attacked by microbes, producing carbon dioxide and — if in water — methane. Both are greenhouse gases, but methane is many times more powerful in warming the atmosphere. Methane also is present in another form, as hydrates - ice-like formations deep underground and under the seabed in which methane molecules are trapped within crystals of frozen water. If warmed, the methane will escape. Dallimore, who has long researched hydrates as energy sources, believes a breakdown of such huge undersea formations may have produced conical “hills” found offshore in the Beaufort Sea bed, some of them 40 meters (more than 100 feet) high. With underwater robots, he detected methane gas leaking from these seabed features, which resemble the strange hills ashore here that the Inuvialuit, or Eskimos, call “pingos.” Canada's pre-eminent permafrost expert, Chris Burn's teams have found the frozen ground warming down to about 80 meters, and he believes the world is courting disaster in failing to curb warming by curbing greenhouse emissions. “I don't think policymakers have woken up to this. It's not in their risk assessments, he said.”
