Tuesday, August 29, 2006

Methane Gas on the Ocean Floor

A very interesting new theory, from UCD, on climate change acceleration related to methane gas stored on the ocean floor.

An excerpt.

A new climate bomb ticking?
Researcher: Warming might free methane on seafloor that could accelerate the crisis
By Matt Weiser -- Bee Staff Writer Published 12:01 am PDT Tuesday, August 29, 2006

Research on ocean sediments near Santa Barbara suggests that climate change could be accelerated by methane gas stored in oil deposits on the seafloor.

The work by Tessa Hill, an assistant professor of geology at UC Davis, documents a new source of methane gas that has not yet been factored into previous analyses of historic climate change.

The findings are potentially troubling because methane is at least 20 times more potent as a greenhouse gas than carbon dioxide, so it has the potential to make the planet hotter faster if released to the atmosphere.

Hill is the lead author of the research, published online Monday by the Proceedings of the National Academy of Sciences, a peer-reviewed journal.

She cautioned, however, that more study is needed before her findings can be applied globally.

For instance, it isn't clear how the methane would be released during climate change, and it is far from certain that similar methane stores worldwide would be freed up as sea temperatures rise.

"We need to learn more about this process, about how globally widespread it is," said Hill, who did the research for her doctoral dissertation at UC Santa Barbara. "But I think we can certainly say this methane seepage out of this source clearly responds to climate warming."

Climate researchers have long been concerned about methane hydrate, a form of frozen methane widespread on the seafloor. If ocean temperatures rise enough to thaw this methane, it could have devastating effects on the climate. But methane stored as a gas in natural offshore petroleum deposits has not yet been figured into climate change.

Hill theorizes that melting methane hydrate could free up the second supply of methane in oil deposits by causing underwater landslides and sinkholes as it melts. But she said this theory requires more research.