September 16, 2007

The Melting Permafrost

Dkos writer oxon wrote today about the melting permafrost and how lakes in Alaska are now boiling due to the release of methane gas. The story he references from Science Daily mentions that researchers are now finding methane bubbles rising from lakes in the Alaskan tundra.

Last month, UAF researcher Katey Walter brought a National Public Radio crew to Alaska’s North Slope, hoping to show them examples of what happens when methane is released when permafrost thaws beneath lakes.

When they reached their destination, Walter and the crew found even more than they bargained for: a lake violently boiling with escaping methane.

The article goes on to say that the boiling methane could be released from natural gas seepage rather than due to the melting of methane hydrates trapped in the permafrost.

Walter said this summer’s fieldwork indicates that methane hotspots, such as the one she and the crew experienced, can come from various sources, not just thawing permafrost. Her next goal is to identify and quantify the sources of the methane hotspots around Alaska.

"It is unlikely that this methane plume was related to permafrost thaw,” said Walter, adding that the methane boiling out of the lake was more likely related to natural gas seepage. “Should large quantities of methane be released from methane hydrates, for instance, in association with permafrost thaw, then we could have large sudden increases in atmospheric methane with potentially large affects on global temperatures."

Yet, just last year scientists in Siberia were reporting lakes were boiling so violently from the release of methane gas that the lakes could not freeze even in the depths of winter. One scientist in Siberia who has been studying the Siberian bogs for 15 years has seen dramatic changes in the past few years.

Many scientists believe that since methane is 20 times more damaging as a greenhouse gas than carbon dioxide, any release of the vast reserves frozen in Siberia could have its own damaging effects on the earth's temperature. Kirpotin says methane is bubbling up so violently in some of the lakes, it stops them from freezing even at the depth of winter.

"It's very difficult for experts to measure exactly how much concentrated methane is being released into the atmosphere. That means the process could be happening many times more quickly than we think."

Some climate skeptics would ask why should we care about methane gas melting in the northern tundra? After all, this just means there's more methane gas that can be used as energy by people.

The problem arises in understanding the sheer scale of the available methane trapped in the northern bogs. First, you need to understand that methane gas is at least 20 times more potent greenhouse gas than carbon dioxide. Although it has a much shorter lifetime in the atmosphere, while it is in the atmosphere it is much more effective at trapping heat in the atmosphere.

So what makes methane?

First some basics: methane (CH4) is a very simple molecule (one carbon surrounded by four hydrogen atoms) and is created predominantly by bacteria that feed on organic material. In dry conditions, there is plenty of atmospheric oxygen, and so aerobic bacteria which produce carbon dioxide (CO2) are preferred. But in wet areas such as swamps, wetlands and in the ocean, there is not enough oxygen, and so complex hydrocarbons get broken down to methane by anaerobic bacteria. Some of this methane can get trapped (as a gas, as a solid, dissolved or eaten) and some makes its way to the atmosphere where it is gradually broken down to CO2 and water (H2O) vapor in a series of chemical reactions.

The northern tundra (and the undersea methane ice) are all the result of massive amounts of biomass being converted to a simpler carbon form in an anaerobic environment. The frozen northern tundra has trapped some 400 gigatons of methane gas for tens of thousands of years. It is the release of this trapped methane that scientists worry about. As I noted earlier this year, the worst case scenarios can be frightening:

Geologists have tied the rapid release of methane gas to the most extreme die-offs the earth has ever experienced.

There are enormous quantities of naturally occurring greenhouse gasses trapped in ice-like structures in the cold northern muds and at the bottom of the seas. These ices, called clathrates, contain 3,000 times as much methane as is in the atmosphere. Methane is more than 20 times as strong a greenhouse gas as carbon dioxide.

Now here's the scary part. A temperature increase of merely a few degrees would cause these gases to volatilize and "burp" into the atmosphere, which would further raise temperatures, which would release yet more methane, heating the Earth and seas further, and so on. There's 400 gigatons of methane locked in the frozen arctic tundra - enough to start this chain reaction - and the kind of warming the Arctic Council predicts is sufficient to melt the clathrates and release these greenhouse gases into the atmosphere.

Once triggered, this cycle could result in runaway global warming the likes of which even the most pessimistic doomsayers aren't talking about.

An apocalyptic fantasy concocted by hysterical environmentalists? Unfortunately, no. Strong geologic evidence suggests something similar has happened at least twice before.

The most recent of these catastrophes occurred about 55 million years ago in what geologists call the Paleocene-Eocene Thermal Maximum (PETM), when methane burps caused rapid warming and massive die-offs, disrupting the climate for more than 100,000 years.

The granddaddy of these catastrophes occurred 251 million years ago, at the end of the Permian period, when a series of methane burps came close to wiping out all life on Earth.

More than 94 percent of the marine species present in the fossil record disappeared suddenly as oxygen levels plummeted and life teetered on the verge of extinction. Over the ensuing 500,000 years, a few species struggled to gain a foothold in the hostile environment. It took 20 million to 30 million years for even rudimentary coral reefs to re-establish themselves and for forests to regrow. In some areas, it took more than 100 million years for ecosystems to reach their former healthy diversity.

That report from EnergyBulletin was written before the most recent studies measuring the release of methane gas were published. No wonder scientists are becoming really worried about global warming and our inability to deal with it.

One comment about the geologic scenarios: the amount of methane gas released into the atmosphere during the worst cases was almost certainly not just the result of methane trapped in the frozen tundra (although it is a very large amount compared to what's currently in the atmosphere) but also the frozen methane on the bottom of the ocean. Here's a brief description of the problem by Nicholas Kristof last year that the scientists at RealClimate praised for it's clarity. And here's an article of how the warming from one degree C to 6 degrees C result from the addition of more sources of greenhouse gases and what the likely results would be for our world. (via truthbeauty)

So what to do? We absolutely need to address global warming fast. This means making sure people like Bjorn Lomborg are challenged and dismissed when he says there isn't any compelling reason to act now. Technologically, we can mitigate the methane by burning it (oxidiation changes it into the less dangerous and more common CO2), but then of course, we will have to compensate for the extra CO2 by reducing our release of other greenhouse gases. A terrific piece that discusses what more we can do is here: Defusing the methane timebomb. (via kafkananda)

One thing is exceedingly clear, we have no more time to fritter away with business as usual. It's time to get a real and focused plan to address global warming now.

Posted by Mary at September 16, 2007 04:42 PM | Environment | Technorati links |
Comments

Greece: conservatives42,6 - socialists38,4 - communists7,6 @ 85% counted

Posted by: ccoaler at September 16, 2007 05:20 PM

Iraq is the focus of many publications.

Posted by: ccoaler at September 17, 2007 04:47 AM

===BlackwaterUSA banned from Iraq===

Posted by: ccoaler at September 17, 2007 11:03 AM

BUSHSHEICH! I SAID BUSHSCHEICH FUME IT!

Posted by: ccoaler at September 17, 2007 02:04 PM

Taser incident in Florida on constitution day

Posted by: ccoaler at September 18, 2007 09:24 AM