Do not try this at home! This cow is a trained
professional.
Dr. Sten Odenwald, an astronomer at the National Institute of Aerospace, writes
Singing the Methane Blues, in which he teaches us the basic foundation facts we need to know about Methane (CH4) to understand is role as the second leading greenhouse gas behind carbon dioxide. He concludes that while carbon dioxide levels, which have already exceeded 400 parts per million (0.04% of the atmosphere), still need to be our primary focus in controlling atmospheric warming, methane levels should be on our radar scopes for the longer-term as well.
Methane (CH4) is a greenhouse gas and contributes to climate change. Colorless and odorless, methane makes up only 0.00017 percent (1.7 parts per million) of the total amount of atmospheric gases. This may seem like a very small amount, but one kilogram of methane has more than 20 times the greenhouse impact to global temperatures as the same amount of carbon dioxide. That means if we put carbon dioxide and methane on the same scale, the 400 ppm of carbon dioxide compares with only a measly 24 ppm of methane. The current value of 1.7 ppm for methane is not much right now, but give it time!
Carbon dioxide has increased by 31 percent since 1750, but methane has increased by nearly five times that amount. More than two-thirds of this methane increase can be attributed to human activities. Long-term atmospheric measurements of methane by NOAA and NASA show that the build-up of methane slowed between 1999 and 2006 to about 17.7 ppm due to reduced industrial emissions and drought in wetland areas, but that changed in 2007. Since then, researchers have seen a growth in methane that has pushed it to 18.3 ppm by 2013.
Methane in the atmosphere. (New Zealand National Institute of Water and Atmospheric Research; and NOAA).
The pie chart below shows that two thirds of the increased methane since 2007 comes from man-made sources not apparently from Arctic warming. A combination of fracking and and wetland outgassing seem to be the biggest culprits.
Dr. Odenwald tells us this could change however, due to concerns about releases of Artic methane accelerating global warming. As one example, he tells us that the highest methane concentrations in North America are found in Lac La Biche in northern Alberta on the edge of the Canadian wetlands where measurements of atmospheric methane as high as 20 ppm with spikes up to 25 ppm have been taken from warming subartic wetlands rich in high carbon peat.
Dr. Odenwald describes a study published in Global Change Biology which examined 71 wetlands around the world where the permafrost is being transformed into wetlands called fens which now leak methane into the atmosphere where they did not before when they were frozen permafrost. He warns that as temperatures rise a point will come when methane trapped in the permafrost will "more quickly dumped into the atmosphere." He says this is currently happening at a rate of about 3.8 million tons/year.
On a more distant time horizon, the warming of the Arctic ocean could also release the deep water stores of methane hydrates which are currently stabilized into solid form by the very low temperatures near the ocean bottom. Currently, this production rate is about 17 million tons per year. That's already about 25 percent of the emissions from domestic gas production and transmission in 2012. A recent USGS assessment of the risks of a major atmospheric Hydrate Bomb places the probability as being very low. "...most of the world's gas hydrate deposits should remain stable for the next few thousand years. Of the gas hydrates likely to become unstable, few are likely to release methane that could reach the atmosphere and intensify climate warming."
This Dr. Sten Odenwald is one character. After scaring the stew right out of us with all of this talk of Artic methane, frozen hydrate methane bombs, and melting permafrost wetlands, in these scary quotes Dr. Odenwald reassures us that our biggest concert should be anthropogenic, aka methane whose origin relates to man, which include cow farts. He mentions recent MIT studies that Arctic methane is expected to contribute to less than 0.1 C rise in temperature by 2100.
Dr. Odenwald's overall conclusion is that for the time being, carbon dioxide should be our most urgent focus of concern as the recent measurements of 400 ppm is the highest in our atmosphere in probably 5 to 24 million years, and that ice core data indicates that carbon dioxide levels have not reached levels this high on year in 800,000 years.
This kind of reassurance reminds me of when I was on a photographic safari at Honeyguide, South Africa many decades ago. Because this was a private reserve, we could get out of the jeeps and trek through the Bush. I asked our wizened old head guide about how to best avoid the 30 different kinds of poisonous mambas and cobras I had read about in the tent, the night before. The warning folder in our tents indicated these damn vipers like to hide under the curls in the little toilet like seats they placed over the outhouse tent. The snakes think this is a little pond where small creatures will come for water. (I still to this day can not sit on a toilet in the dark without turning on the light and checking it first. I'm serious. Some ways to die are just too terrible to even imagine.)
The guide laughed and said, "son, don't worry about the snakes, you are far more likely to be killed by a stampeding hippo or rhino. And, he was right, I came within about 8 feet of being trampled by an enormous mother white rhino we had tracked for four hours, when her baby got spooked and ran right past us.
So folks, the lesson of this paper is, "don't worry about those methane hydrate bombs causing the ice caps to melt, because it is far more likely sea levels will rise first due to your local coal plant sending out carbon dioxide."
And, Dr. Sten Odenwald seems to have the facts behind him and is not just blowing a lot of hot air.
Have a nice day!