George Monbiot, talking about methane hydrates/clathrates, nails it (Japan’s gas reserves are worthless if we take climate change seriously) [emphasis added]:
There’s only one way of knowing whether or not governments are serious about climate change: have they decided to leave most of their fossil fuel reserves in the ground? We have already discovered far more carbon than we can afford to burn, if we are not to commit the world to very dangerous levels of heating. Only if most of it – four-fifths according to a detailed estimate – is left where it sits is there a good chance of preventing more than 2C of global warming.
Forgive me if you’ve heard me say this many times before. But it is the only point that is really worth making. It doesn’t matter how many wind turbines you build, or energy-saving lightbulbs you install, or more economical cars you manufacture: unless most of our fossil fuel reserves are declared off-limits they will, sooner or later, be extracted and burned. The question of whether it is sooner or whether it is later makes little difference: we have already identified more underground carbon than we can afford to burn between now and the year 3000.
The US Geological Survey warns that clathrates could contribute significantly to climate change. Yet it also boasts that the “first goal” of its clathrates project “is to contribute to research that may lead to the development of gas hydrates as a potential energy source.” They know what they’re doing, and they don’t care.
But this is not to say that there will be no catastrophic release of gas from methane hydrates buried beneath the deep sea. If it happens within this century, it will be the result not of global warming but of the process the Japanese government has now pioneered: extracting gas in order to burn it. Like all the nations which continue to extend the fossil fuel frontier (such as Britain, where companies intend to start producing gas through fracking) Japan is adding to the mountain of fossil fuels we cannot responsibly burn. The brave new technology it has developed, now lauded in the media, would be worthless in a world that took climate change seriously.
As I quoted in an article just yesterday (Checkpoint), the current estimates are that the amount of carbon in methane hydrates, worldwide, is at least double that in all other fossil fuels.
In its annual Outlook for Energy, ExxonMobil doesn’t even include methane hydrates in its projections of unconventional natural gas resources. It limits those to deep water and horizontal drilling, and fracking. And even so, it projects natural gas usage worldwide to look like this:
And it thinks our worldwide CO2 emissions from energy use will look like this:
Anyone here care to speculate about how much trouble we’re in, climate-wise, if ExxonMobil’s emissions projections are even remotely in the ballpark?
Anyone here care to estimate what will happen to our emissions if the technology for extracting methane hydrates takes off? Sure, coal will dwindle in use pretty quickly, although likely not as quickly as the US ditched oil as a way to generate electricity in the years following the first oil embargo. But we’ll still likely be locked into oil as our dominant transportation fuel for decades, and our budding romance with natural gas won’t be much help, as it will only lock us into too high emissions. As I’ve pointed out repeatedly, natural gas fueled vehicles only reduce per mile CO2 emissions by about 20% compared to an equivalent gasoline fueled vehicle. And if we want to convert that delightfully plentiful and cheap natural gas into hydrogen to fuel our brave new world of fuel cell vehicles, then we better come up with a rock-solid carbon capture and storage infrastructure in a hurry: Every kg of hydrogen liberated from natural gas via reforming (by far the most commonly used technology) also creates about 5.5 kg of CO2.
Oh, and before anyone jumps on the electrolysis bandwagon as a way to produce massive amounts of hydrogen, please bring numbers showing how much electricity it will require (answer: a lot) and what the carbon footprint is of said moving electrons.
And in either case, there’s the added footprint/cost of transporting and then compressing hydrogen to high pressure so it can be used in on board fuel tanks.
But I digress.
The point is that we simply have to find a way to resist the siren call of cheap fossil fuels and force ourselves to resort to the ultimate form of carbon sequestration — leave it in the ground. If we don’t — and I’m guessing Japan will be far from the only country to make a huge move to mining hydrates — the long run costs in both human and monetary terms will be hideous and last for many decades.
 See Wikipedia’s entry on steam reforming and plug in the atomic weights of hydrogen, carbon, and oxygen, and you get 44 units of CO2 for every 8 of hydrogen produced, or a ratio of 5.5:1.
 Yes, compared to a gasoline or diesel fueled car, 5.5 kg of CO2 for the 50 miles, say, a compact car can drive on 1 kg of hydrogen is a big improvement, but we have to look at the long term: What level of emissions are we willing to lock into with massive infrastructure investments? As someone (Ken Caldeira?) once observed, asking about the right level of CO2 emissions is like asking about the right level of muggings of little old ladies: The only correct answer is zero.
 The hydrates aren’t located in just a few choice areas, after all: