(Just a note: The giveaway period for the audiobook of The Poisoner’s Handbook has ended. If your comment is not published, it’s too late to be considered for a free copy. But still glad to hear your ideas! Winners to be notified on Wednesday).
One of the most interesting – and I think important – comment threads on this blog has concerned risks posed by the gas methane, blamed (along with BP) for the devastating oil spill in April and still seeping into the water from the broken drill pipe.
“We don’t know the composition of the crude oil as it is leaving the well head. This crude is reported to have a very high methane content,” wrote one smart reader, noting that one of the greatest risks related to methane (composed, by the way, of one carbon atom to every four hydrogen atoms, CH4) is that as bacteria break it down, the metabolism process can involve sulfates in the water and lead to formation of the much more poisonous gas, hydrogen sulfide (two hydrogens for every one sulfur, H2S).
I was reminded of unanswered questions about methane while reading a recent piece in Newsweek entitled “What the Spill Will Kill” which reports that “Giant plumes of crude oil mixed with methane are sweeping the ocean depths with devastating consequences.”
What devastating consequences exactly I wondered and did the presence of methane make a difference, in how the plumes formed, in how poisonous they were. But the article didn’t answer those questions, partly because this is all one big chemical experiment and partly because methane in water lacks the obvious drama of poisonous chemical dispersants and toxic and visibly murderous crude oil.
But let’s pay methane a little respect here. By all accounts, BP and its cohorts were remarkably careless in managing methane risks in their deep-sea drilling. It’s common knowledge that where we find fossil fuel deposits be they coal mines (see earlier post, The Methane Calculation) or oil deposits, they’re accompanied by methane which is primary component of “natural gas” (the user-friendly named coined by big energy companies.)
At the bottom of the Gulf of Mexico, at what we’ll call BP oil spill depth, almost a mile down, a combination of high water pressure and low temperatures – reportedly hovering just above freezing, around 34 degrees fahrenheit – methane tends to form into ice-like crystalline structures, called methane hydrates or clathrates. You may remember that this icy version of methane stymied one of BP’s first efforts to put a containment dome over the leaking riser pipe. By the way, the oil industry is now working to mine methyl hydrates, which change into gaseous methane as they rise, warm, and depressurize, and harness them for energy.
One of the theories of the BP disaster is that a chemical reaction, perhaps triggered by the compounds used for sealing cement around the drill hole, caused rapid heating, converting hydrates to a soaring building up gas, which rocketed up the pipe to the rig. Methane being highly flammable – as anyone owning a gas stove knows – was ignited by sparks coming off equipment off the rig, triggering the horrifying fiery explosion that followed.
But back to the bottom. At depth, the Gulf of Mexico is unusually rich in methyl hydrates, so much so that it supports a flourishing community of methanotrophs or methanophiles- methane-digesting bacteria – and also a community of very strange creatures called ice worms that live on the bacteria.
Which is another way of letting us know that there’s a lot of methane down there. In fact, by some accounts the hydrocarbons pouring out of the BP leak (yes, I do enjoy making that connection) are about 60 percent crude oil and 40 percent methane. In fact, so much methane has been pouring into the gulf – by one estimate a million times more than from the natural seepage – that scientists are now preparing to measure the extent of the spill’s reach – those underwater plumes, in fact, by tracking methane.
Very handy, you might say. But the more interesting point is that the scientists tracking these plumes believe that their massive spread underwater is largely being driven by the methane component in this leak. To quote the Gulf Oil Blog of the University of Georgia Department of Marine Sciences: “Think of it as gas-saturated oil that has been shot out of a deep sea cannon under intense pressure – it’s like putting olive oil in a spray can, pressurizing it and pushing the spray button. What comes out when you push that button? A mist of olive oil. This well is leaking a mist of oil that is settling out in the deep sea.”
There are also those who believe that an excess of methane in water is poisonous to fish. Part of this argument is that fish are designed to take in dissolved gases through their gills, making methane fairly insidious. There’s some evidence that shows that high concentrations of methane are harmful to the nervous system and circulatory system of many fish species. To be fair, not everyone considers this a serious problem; methane is not the most reactive of gases in terms of toxicity.
But it all adds up to a reminder that this isn’t just an “oil” spill. It isn’t just about what we see. It’s also about what we don’t see. And the time to acknowledge that – and here’s an idea, actually try to do something about it – happens to be now. That would be: NOW.