Fig. 1. Thawing permafrost. Image credit – Edward A.G.Schuur, University of Florida
Permafrost is a subject in the climate change debate I have tried to not think about too much. It is just too scary to think about the vast amounts of carbon stored in frozen soils, ready to be released if global temperatures keep rising. But it seems to be time to finally take a closer look at what is happening in the most northern areas of our planet.
Areas like the northern parts of Siberia, Alaska, or Canada are cold enough that most parts of the ground are frozen – that is why it is called “permafrost” (Fig. 1). Only the uppermost layer is thawing in the summer, and gives room for plants to grow. This active layer can be 0.6 to 4 m thick. Even though some of the plant material decomposes, quite a bit of it does not. This is because the active layer is frozen during large parts of the year; and microbial processes that decompose organic material are significantly slowed down at low temperatures – the soil acts like a freezer for organic material.
When air temperature increases, then of course the soil warms as well: the active layer will stay unfrozen for a longer period of time during the year, and the deeper, permanently frozen area will start to thaw. At the same time, warmer temperatures increase microbial activity. Microbial activity, in turn, produces its own heat. With that, the decomposition of organic materials in the soil will proceed not only over a larger time span and over a larger area, but also at an accelerated rate. This positive feedback loop will accelerate with further warming, and could ultimately trigger an “irreversible process of thawing.”
But why is the decomposition of organic material so worrisome? Decomposition means that an object is falling into its parts. And a large part of the decomposing organic material stems from plants. To really understand what is happening in the Arctic we therefore need to shortly take a look at photosynthesis (Fig. 2):
Plants take up water and carbon dioxide, add a bit of sunlight and nutrients, and assemble all this during the absolutely amazing process of photosynthesis into a completely new structure: sugar, with the “waste product” of oxygen.
Fig. 2. Photosynthesis and decomposition. Picture from Wikipedia
In reverse, during decomposition sugar molecules and oxygen react with enzymes that decompose sugar to water and CO2; or, under unaerobic circumstances (i.e., without oxygen, such as in soils underneath lakes), the sugar molecules decompose into other molecules, including methane (CH4). Both CO2 and methane are very potent greenhouse gases. The thawing of permafrost thus releases vast amounts of greenhouse gases.
Fig. 3. Measured (1995-2003) and calculated (1930-1995) averaged over the year soil temperatures in Fairbanks, Alaska area
But is permafrost thawing already? You bet it does. Indeed, in some areas permafrost has warmed by up to 3ºC within the last decades (Fig. 3). In some areas, temperatures of the permafrost are getting dangerously close to above freezing. In fact, in some areas, soil temperature has already passed the thawing point (see references at NOAA) .
Just how much organic material is stored in the permafrost has so far been “hugely under-estimated.” A new report indicates that the amount of carbon stored in permafrost around the North-Pole might bee twice as high as previously thought (CSIRO).
Executive Director of the Global Carbon Project at CSIRO, Dr Pep Canadell, mentioned that
“Projections show that almost all near-surface permafrost will disappear by the end of this century exposing large carbon stores to decomposition and release of greenhouse gases.”
According to these new estimates, a thawing of about 10% of the Arctic soil would release about 80 ppm CO2. Global temperature would then increase on abverage by about o.7ºC.
Considering
- that we are already above the CO2 concentration that is considered relatively safe for the future of human civilization (350 ppm CO2)
- that in June 2009 we reached 390 ppm CO2
- that a global increase in temperature above 2ºC will likely cause the passing of irreversible tipping points, and
- that we are already almost committed to a global increase in temperature to 2ºC,
this estimate is extremely worrisom – to say the least.
Even though it is important to clearly understand what will happen if we do not act in time, let’s not worry too much about what could happen in case of inaction. Instead, let’s focus on what we need to work towards:
We need a carbon free energy future which is exclusively supported by truly renewable energies like the sun, wind, water, and geothermy within the coming decades. Such a “Great Transformation” will only be possible with vast energy savings through energy efficiency and through a change in our behavior, wasting much less energy than we do now. We must not be satisfied with half measures. Without effective fast action, all our efforts will likely be to no prevail.
Maiken Winter
More information:
http://www.csiro.au/news/Permafrost-climate-change-threat.html
http://www.reuters.com/article/africaCrisis/idUSSP458218
http://www.arctic.noaa.gov/essay_romanovsky.html
Tags: Arctic, Canada, CO2, CSIRO, melting, Methane, permafrost, Siberia, temperature
Ok let me get this straight, you state that in a new study “the amount of carbon stored in permafrost around the North-Pole might be twice as high as previously thought“ and then you state that the study was done by the Global Carbon Project at CSIRO. Surely you don’t think that this study won’t be biased? Oh my Lord, come on now! LOL!
You know, these kinds of reports do nothing good for our Green Movement. They make us look like a bunch of hysterical worry-warts, and they might as well be paid for by Exxon. We don’t need this kind of BS right now.
It’s always good to think about where a statement comes from. For example, most major skeptics are funded by places like Exxon, or other places that make a lot of money by making them believe that we can keep burning coal and oil the way we have.
The Global Carbon Project might sound like a place that gets money from selling carbon credits. So by scaring people they might find more buyers.
Unfortunately, there is hardly a way to make the state we are in sound too scary. Second, the global carbon project has nothing to do with making money from carbon credits (see:http://www.globalcarbonproject.org/index.htm where it says “The scientific goal of the project is to develop a complete picture of the global carbon cycle, including both its biophysical and human dimensions together with the interactions and feedbacks between them.”).
I’m not a scientist, although my grades were good enough in chemistry. I am, however a student of everything. One thing proven by Quantum physics, is that the mind is capable of making matter. If thoughts are things, we really need to find a positive way to turn this around. Plant more trees. Anything else? How can we heal it?
Tree plantings are great; most of all, they are fun and get people outside and to appreciate nature. But they won’t safe us from ourselves. More important is not causing more trees to be cut (e.g., not buying non-recycled paper or cheap wooden products or eat alot less meat, and of so, organic, as a lot of soy-beans are planted in former rainforest ares to be exported to feed our cattle). But most important is to not support the fossil fuel industry: buy green electricity, put up solar panels, safe energy wherever you can, stop using driers, clothes can dry in the air, don’t drive everywhere, participate in car sharing, petition for more bike lanes and more bus routes and trains. Don’t do laundry all the time, unplug your standby..there is lots and lots of easy things to do. And be wlling to make sacrifices. There is just no way around it. But the good thing is that what seems like a sacrifice ends up as a blessing soon.
And very most important: go talk to your major or other representatives about what you expect him or her to do to solve the climate crisis.
Thank you for your help!