Climate scientists have long been concerned that rising temperatures in the Arctic, brought about by human caused global warming, could enhance the release of Arctic methane. The methane is stored on the sea bed in the form of methane hydrates, a form of frozen methane that is very unstable. Methane is also locked up in decayed biological matter on the tundras surrounding the Arctic or in the submerged tundra of the East Siberian Arctic Shelf.
The volumes of carbon-based methane stored in this way are large. Larger, in fact, than all the carbon released by humans through the burning of fossil fuels since the industrial age began. In addition, methane provides a powerful kick to the climate system. Over the course of a hundred years it traps 20 times more heat than CO2, before turning into CO2 and adding even more insult to injury. So even a relatively small fraction of this methane making its way into the atmosphere can have a very significant impact.
The concern of some scientists is that the initial warming caused by human emissions of CO2 and other greenhouse gasses will result in a forcing powerful enough to unlock this methane. To unlock it in high enough volumes that it creates a kind of runaway feedback loop (see Amplifying Feedbacks).
Unfortunately, research in this very new field does indicate increasing releases of methane from the Arctic. Research conducted last year found very large plumes of methane bubbling up from the East Siberian Arctic Shelf. Many have cautioned that we shouldn’t draw too many conclusions from these early indications, despite the fact that previous observations found methane plumes measuring about 10 meters across, while later observations found methane plumes in the same region measuring more than 1 kilometer across.
Now, satellite data compiled by the University of Maryland provides observations of methane release from space. The Atmospheric Infrared Sensor (AIRS) is aboard NASA’s AQUA satellite and has provided a record of increasing methane release over the Arctic since 2003. You can view a slide-show of 2003 through March of this year below:
The months when methane release tends to pulse higher is from October through February, with the most intense pulses occurring in January. Just look at these two images. The first is from January of 2003, the other from January of this year:
As you have probably noticed, there is a striking difference between the methane concentration in the January, 2003 image and that in the January, 2012 image. And based on the trend established in the period shown, we can clearly see we have an amplifying methane release over the past nine years.
When added to observations of amplifying methane release from the seabed, a proliferation of melt ponds over the Arctic tundra releasing high levels of methane, a general melting of the Arctic tundra resulting in the release of methane from decaying material there, and now this series of satellite observations, it appears that we have solid evidence of an amplifying methane pulse in the Arctic. And this is cause for serious concern because it is a powerful feedback to the already strong climate forcing of human greenhouse gas emissions.