Methane Poses Climate Risk, Energy Opportunity

Methane reserves deep in the ocean and in arctic permafrost might trigger runaway global warming. But they've also got the potential to provide huge amounts of power, a possibility that is attracting the interest of energy companies.

Methane hydrate, a strange form of natural gas, has recently become a fascination for energy-hungry nations from the United States to Japan and India. Hydrate is found in oceans across the world, where the gas is trapped in icy structures below the seabed, and also lies beneath the Arctic's permafrost.

A paper published this week in Nature suggests that the release of methane hydrates, also known as clathrates, may have triggered a very rapid period of global warming 635 million years ago -- and may do so again. But those same hydrates are also a tempting target for energy production.

"What we've been asked to do is to make this a viable option for the policy makers in the future, and to figure out what's available to us," says Ray Boswell, a researcher with the U.S. Department of Energy's methane hydrates R&D; program. "You don't want to find out that you need it, and then find out that you're 30 years down the science and technology curve."

The Gulf of Mexico is estimated to hold more than 6,500 trillion cubic feet of hydrate in sandstone reservoirs, currently the best candidates for commercial exploitation, according to the U.S. Minerals Management Service. If only 5 percent of that hydrate could be tapped, it would yield more than 300 trillion cubic feet of gas. By comparison, the United States' reserve of conventional natural gas is currently estimated at 211 trillion cubic feet.

Researchers romantically call methane hydrates "the fire in the ice," since the frosty chunks burn if you set a match to them. But it's not just romance that's drawing energy companies to the frozen fuel. While methane hydrates have previously been too expensive to extract on a commercial scale, the increasing price of oil -- now more than $130 per barrel -- means the hydrates might soon become a profitable energy source. Chevron has been involved in the gulf research, and BP is exploring for hydrates in Alaska. Japanese engineers reportedly pumped hydrates from a test well in Canada's Northwest Territories this last winter.

"Everybody knows there's a lot of it," Boswell says. "Now, our goal is to understand the ramifications: Does it have potential as an energy resource, and if so, how would you go about getting it? And how does it fit into climate issues?"

It's that last question that opens up the can of worms. Even as some researchers wonder whether methane hydrate could play an important role in powering the 21st century, others ask whether it has played a critical part in catastrophic climate shifts in the past -- and if it could do so again.

The troubling questions arise from prehistoric climate blips that researchers are still struggling to understand.