Gas hydrates in ocean could trigger catastrophic climate change

Ocean gas hydrates could trigger catastrophic climate change

Rhett A. Butler, mongabay.com

September 6, 2005

Global warming will cause gasses trapped beneath the ocean floor to release into the atmosphere according to research [1] presented at the Annual Conference of the Royal Geographical Society [2]. The impact could initiate a catastrophic global greenhouse effect.

Mark Maslin, Senior Reader in Geography at University College London and a senior researcher for the London
Environmental Change Research Centre, looked at the impact of increasing global temperatures on gas hydrates’ such as methane that exist in solid deposits at the bottom of the ocean and in permafrost on land [3][4]. According to Dr. Maslin, such a temperature rise could destabilize these deposits and trigger a massive release of methane gas into the atmosphere. Methane is 21 times more powerful than carbon dioxide as a greenhouse gas. This would result in a further rise in global temperatures and in doing so, would initiate the release of even more gas hydrate causing a runaway greenhouse effect. Gas
hydrates from total reserves could contain up to 10 times the current amount of carbon into the atmosphere.

“The destabilization of gas hydrates is likely to be a serious hazard in the near future due to
the effects of global warming,” says Dr Maslin. “Research already exists to suggest that the release of hydrates increased
global temperature 18,000 years ago, and we now face a similar threat as our global temperature continues
to rise.”

Rapid climate change is of particular concern to scientists because it could significantly impact human agriculture, cause changes in sea levels and flood low-lying cities, and produce stronger storms and hurricanes. Late last month an atmospheric scientist at Massachusetts Institute of Technology released a study in Nature that found hurricanes have grown significantly more powerful and destructive over the past three decades. Kerry Emanuel, the author of the study, warned that since hurricanes depend on warm water to form and build, global climate change might increase the effect of hurricanes still further in coming years. Just last week Hurricane Katrina devastated the Gulf Coast of the United States. The damage from the hurricane was blamed less on climate change than on its destructive path and the loss of protective ecosystems like wetlands and forests around New Orleans.

Of further concern, a study released in late August suggests that a dramatic rise in carbon dioxide 250 million years ago may have caused global temperatures to soar and result in Earth’s greatest mass extinction, the Permian-Triassic extinction event. Global warming, which may have produced temperatures 10 to 30 degrees Celsius higher than today, would have had a significant impact both on oceans, where about 95% of life forms became extinct, and on land, where almost 75% of species died out.

While climatologists are anticipating much more moderate ocean temperature change over the coming decades, models predict that if currents rate of warming continue, sea temperatures could still be elevated by as much as 5.8 degrees centigrade by 2100.

Dr Maslin adds that there is another fear with regard to such a scenario. He says, “a sudden explosive release of gas hydrate reserves beneath the ocean could initiate a continental slope failure, which could lead to tsunami of up to 15 meters high.”

Tsunamis, stronger hurricanes, flooding — climate change should be of serious concern to politician and business leaders alike.

This article is based on a paper released by the Royal Geographical Society.

Notes