This is certainly not the first time I've mentioned, and probably not be the fist time you've noticed, how carelessly the terms alternative energy, clean energy and green energy are bandied about, as if they mean exactly the same thing.
What occasions me to repeat this complaint is the revival of the television series "Dallas," which epitomized everything we love to hate about oil. In the new version, says New York Times television correspondent Alessandra Stanley, "the writers have reconstituted the feuds of the second generation of Ewings as an allegory about clean energy versus fossil fuels." Thus Christopher Ewing, nephew of the infamous J.R. (photo), "has turned his back on drilling and wants to develop methane hydrates as an energy source."
There are a couple of problems here, at least as the setup is described by Stanley. Methane hydrates, or methane clathrates if you prefer, are fossil fuels; and unless perfectly extracted—an art still waiting for a virtuoso performance—they are not necessarily clean.
The so-called hydrates or clathrates are cystalline solids (consisting generally of methane, the basic constituent of natural gas) which happen to be trapped in ice deep under oceans. In terms of available energy, the amount of gas hydrates may be twice the world's total conventional fossil reserves, according to the U.S. Geologic Survey. If safe and practical extraction methods can be found, they could obviously contribute significantly to world energy resources.
The rub is that methane is an extremely potent greenhouse gas, ten times as effective per molecule as carbon dioxide in causing global warming. If the ice surrounding the hydrates were to melt as a result of warming and the trapped methane were liberated, the effect would be to accelerate warming. "Methane released as a result of landslides caused by a sea-level fall would warm the Earth, as would methane released from gas hydrates in Arctic sediments as they become warmed during a sea-level rise," says the USGS.
In fairness, the term "alternative energy" is a bit slippery, inasmuch as it's often used without specifying what something is alternative to. This is why it so easily lends itself to use as a synonym for "clean" or "green" or "renewable," which it is not. So the Times correspondent may be forgiven for having written a little carelessly (even though, let it be said, she attained such a reputation for carelessness that the Times assigned her a special factchecker several years ago).
Having not seen the episode in question myself, I cannot attest whether the writers got the distinction between clean energy and alternative energy right. But a detailed recap of the premier Dallas episode posted on one website refers only to a proposed methane extraction plant and a dinner argument concerning alternative energy versus oil, without saying anything about clean energy. However, in an interview with the Wall Street Journal, the actor who plays Christopher Ewing, a young fellow by the name of Jesse Metcalfe, says he took the part "because my character is trying to pull the family away from the old way of doing things into the more environmentally friendly fossil fuels."
So Metcalf gets credit for being half right. He recognizes that the methane hydrates are a fossil fuel. But whether they are environmentally friendly remains to be shown.