Global Warming and Methane Under Pressure

When I first watched An Inconvenient Truth, I went to the special features on the DVD and watched the follow-up interview with Al Gore. He spoke about recent research about global warming that had come out since the shooting of the film, such as information about a link between hurricane intensity and global warming. But far more disturbing than that was a discussion of how global warming could cause the tundra to thaw enough to release methane and carbon dioxide into the atmosphere, further compounding the problem.

Think of it as twisting the cap too fast on a soda bottle that has been shaken. After that seal is broken, the carbon dioxide in the bottle rapidly bubbles up, and nothing can stop the inevitable horrid mess. You just want to get out of the way of it.

Obviously, that’s not an option for us if the permafrost thaws.

But I wanted to see for myself. Gore’s interview didn’t go into great detail about what might happen if this occurred, and I wanted to see just what the ramifications of it could be.
This article from the Energy Bulletin was written in late 2004, so the science isn’t brand-new by any means. But the article was far more horrifying than Gore’s interview:

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.

Uh, what?

The great Permian extinction was nothing new to me. Although less famous among the non-geologist non-paleontologist set than the Cretaceous extinction that killed the dinosaurs, anyone who’s ever read many National Geographics knows about this event. And I knew it was probably triggered by a rapid change in climate. However… methane releases causing it? I had to see if this was based in fact.

Well, it appears that it was.

The Wikipedia article on the Permian-Triassic extinction offers a list of explanations for it, along with descriptions of the likelihood and evidence for each. Here they are:

  • Continental drift: When the continents joined into one massive landmass, this affected the oceans, causing extinction of some marine life. However, it’s considered insufficient to account for close to 95% of life on Earth dying.
  • Impact of a celestial body: An asteroid, meteor, or comet may have struck Earth, as happened at the end of the Cretaceous era. There is no direct evidence of this, though, and apparently everything claimed as evidence has fallen into serious question.
  • Supernova: A star could have supernova’d relatively close to the solar system, causing radiation that would wipe of most of the life on the planet. It’s possible, but there is no astronomical evidence that one occurred.
  • A spike in volcanic activity, causing global warming that disrupted the climate system, shut off oceanic currents, deprived the ocean of oxygen, and triggered the release of methane trapped in the sea. That Energy Bulletin article says that methane is far stronger than carbon dioxide as a greenhouse gas, and it would have caused an additional 5 degrees Celsius rise in temperature on top of what the volcanism-induced global warming had already caused. What’s more, there is considerable geological evidence to support this theory, as compared with the rest of the extinction theories. It’s all in the article, and it would amount to quoting the entire piece if I put the relevant parts here. It’s there; read it for yourself and be freaked out just as I was.

Of course, nothing like that could happen again.

Right?

Well, realistically, that probably is a doomsday scenario. It’s only happened once in the entire history of life on Earth, although there was another pretty bad event that took place in the Cenozoic Era. However, the central theory behind the foreign and domestic security policy of the United States has been to prepare for the most minuscule possibility of a worst-case scenario. Ron Suskind wrote a book about this idea called The One Percent Doctrine. I don’t know about you, but — without any intention of minimizing terrorist activity — as far as I’m concerned, the mass extinction of most life on Earth is a bit larger of a potential problem than a terrorist attack. If ever there’s an appropriate use of “the one percent doctrine,” it would be to prevent a mass extinction.

In Al Gore’s interview about this problem, he says that “it’s not a good thing” when methane is released into the atmosphere. I would nominate that for understatement of the year.