If you look at the annual methane fluctuations in the Arctic — the region where peak global values tend to crop up — highest readings typically occur during the September-through-October time-frame and then again in January.
Over the past few years, peak values have ranged as high as 2600 parts per billion during the fall of 2014 and then again during January of 2015. Typically, peak values then subside as Northern Hemisphere Winter locks in most of the emitting High Latitude sources and we wait for the Autumn and early Winter overburdens to again emerge. So those of us who keep track of methane kinda just sat tight, expecting at least a somewhat calm spring, and waited for the new peak values that would be most likely to pop up by late this year and early next.
But then, on Saturday, this popped up in the NOAA METOP measure:
(NOAA METOP methane measure finds peak values as high as 2845 parts per billion. An extraordinarily high reading, especially for April. Image source: NOAA OPSO.)
A whopping peak value of 2845 parts per billion at the 14,000 foot level of the atmosphere where methane concentrations tend to top out — especially in higher level clouds that have tended to be associated with Arctic wildfires. A value more than 200 parts per billion higher than daily peaks during January of 2015. All-in-all, a huge and unexpected jump at a very odd time for it.
If we look at the above map we find that most of the peak values are in the region of Russia. With many peak values in areas where major wildfires have been ongoing (Lake Baikal region, Khakassia), where wildfires were just starting to flare up (Northern Ukraine), or above other recently thawing permafrost zones. We also find decent spikes over China, Europe, Iceland, spots of the High Arctic, Canada and Alaska, Central Africa, The Indian Ocean, and over Antarctica.
Daily Mean Values Pop as Well
Sam Carana over at Arctic News caught the spike earlier this week and provided this very informative graph cataloging 14,000 to 18,000 foot methane levels for 2015:
(Daily mean and peak values provided by Sam Carana show how much of an outlier the April 25 spike is. Image source: Arctic News.)
And what we find, from looking at the graph, is that not only did peak values spike to an extraordinary high level in late April, but mean values also took a big jump — rising from 1807 ppb on January 10 to a peak of 1829 ppb on April 22nd. A 12 parts per billion bump in the entire global measure over a four month period (average annual rates of increase have been in the range of 7 parts per billion each year recently). A raging pace of increase 5 times faster than the annual trend.
It’s worth noting that daily peak and mean values do tend to swing back and forth quite vigorously. As an example, a peak mean value of 1839 ppb was recorded on September 7 of 2014. But, as noted above, these are extraordinarily abnormal high values for April. A quite unsettling methane spike at a very odd time of year and happening on dates and over locations that may suggest permafrost zone fire involvement.
Conditions in Context
For context, methane is an extraordinarily powerful greenhouse gas with a global warming potential about 30-40 times that of CO2 over meaningful timescales. Global atmospheric averages for methane have jumped from around 725 parts per billion during the 18th Century to above 1820 parts per billion now. A major scientific controversy is now ongoing over the issue of how rapidly global carbon stores will respond to an extraordinary pace of human warming — with some observational specialists raising the possibility of a very large methane contribution from now activating carbon stores in the Arctic.