With multiple projects underway already focusing on finding the next big renewable energy source above water and below the surface (and even on other planets), it was only a matter of time before researchers turned their attention to one of the few remaining untapped areas — the vast expanse beneath the ocean floor. Now a team of scientists from the University of Haifa and Stanford University are getting ready to embark on a research expedition with the aim of investigating the use of a gas lying beneath the floor, most likely methane, as an alternative to oil.
According to a recent article in The Economist, methane hidden beneath the ocean floor may make up "the world's greatest store of fossil fuel" — some experts estimate that its reserves could be as much as twice the rest of the world's fossil fuel supplies combined. Methane is typically stored in structures called methane hydrates, or clathrates, which are little cages of water molecules with methane molecules trapped inside. They tend to form in areas where pressures are high and temperatures are low; thus, they are often seen lining the floor at the continental shelves and are also found locked within the poles' permafrost.
Yet methane is far from being an ideal silver bullet to solve our global energy woes: as many already know, it is a potent greenhouse gas (worse even than carbon dioxide) and, when stored within clathrates, is extremely unstable. In addition, even when looking at it from a purely business-centric point of view, clathrates may not be as valuable since they only tend to yield a tiny fraction of the enclosed methane and mining them will be difficult, not to mention very risky. Improper extraction techniques would likely result in a speedier release of the gas to the atmosphere — a dangerous consequence that would worsen the effects of climate change. Mass methane gas releases from clathrates are actually thought to have played a major role in two past global temperatures hikes that led to large-scale extinctions about 250 million and 55 million years ago.
That is not to say that we will never be able to use methane as a source of energy. One potential solution that is currently being studied consists of pumping carbon dioxide into the clathrates, which would help stabilize them (making methane extraction much more feasible) and sequester the carbon dioxide at the same time. The small amount of heat generated in the process would help keep the reaction going. With this idea as well as any other, of course, the trick is ensuring the potential negative repercussions don't far outweigh the benefits.
Via ::The University of Haifa Media: Alternative energy (press release), ::The Economist: The great submarine burp (news website), ::Northwest Science & Technology: Methane Mimosas On Ice