The blogosphere is humming with alarm over Japan’s methane clathrates extraction from the seabed. There is estimated to be as much carbon tied up in methane there as there is in the rest of the biosphere/atmosphere. That’s definitely something to give one pause.
I haven’t done a full analysis on the impact of burning seabed methane. To do it, I’d have to use the Global Climate Modeler (GCM) – which I have done before. It’s at least a month’s project. But I can talk about the complications and start people thinking.
The core concept is Global Warming Potential (GWP), but it’s not simple. Methane has a GWP of 21-25 (e.g. 21-25X CO2 per ton. Different sources had different values.) So burning methane lowers GWP. But 2.75 tons of CO2 are produced per ton of methane burned. So the reduction in GWP by burning methane is about 8-9 times.
But methane has an atmospheric half-life of 7 years, while CO2 has a half-life of around 70. To drop to 1% of what it was takes about 6 half-lives. (Half-life progression goes: 100%, 50%, 25%, 12.5%, 6.25%… etc.) For 90% of released methane to disappear takes a bit over 21 years. To become negligible takes 42 or so.
On top of that, the methane clathrates in the seabed are scheduled to float to the surface over the next 50-100 years in a “big fart”. That will spike the amount of methane intensely. If just 20% of methane clathrates do that, we will suddenly have the equivalent of 5 times the total amount of CO2 warming the globe that we have now. That will cause more methane to release, and probable we will have 5-10 times the GWP total in the world that we have to day for somewhere around 150-200 years. (If we don’t burn it.)
Let’s say we are able to burn 10% of the methane clathrates. (That’s a huge amount.) Then we will have roughly 4.55 times the amount of GW gases that we do today instead of 5X. The .05 is from the CO2 we from burning methane clathrates.
Methane clathrates have already been bubbling up. First reports of refrigerator chunks of “fizzing white ice” on the surface of the ocean were in the 1990’s.
So, it looks to me like it’s best that we mine it like made and burn it.
Our alternative is to shut down 100% of carbon burning and convert over to nuclear power and/or satellite solar power. But the way we are going, with the “party of no” in charge? Saying “No!” means that carbon will be burned.
So may as well go after it.