From the University of Guelph
Wetlands Likely to Blame for Greenhouse Gas Increases
A surprising recent rise in atmospheric methane likely stems from wetland emissions, suggesting that much more of the potent greenhouse gas will be pumped into the atmosphere as northern wetlands continue to thaw and tropical ones to warm, according to a new international study led by a University of Guelph researcher.
The study supports calls for improved monitoring of wetlands and human changes to those ecosystems – a timely topic as the Intergovernmental Panel on Climate Change prepares to examine land use impacts on greenhouse gas emissions, says Prof. Merritt Turetsky, Department of Integrative Biology.
Turetsky is the lead author of a paper published today in Global Change Biology based on one of the largest-ever analyses of global methane emissions. The team looked at almost 20,000 field data measurements collected from 70 sites across arctic, temperate and tropical regions.
Agnieszka Kotowska, a former master’s student, and David Olefeldt, a post-doc at Guelph, also were among 19 study co-authors from Canada, the United States, the United Kingdom, Finland, Germany and Sweden.
One of the strongest greenhouse gases, methane comes from agriculture and fossil fuel use, as well as natural sources such as microbes in saturated wetland soils.
The amount of atmospheric methane has remained relatively stable for about a decade, but concentrations began to rise again in 2007. Scientists believe this increase stems partly from more methane being released from thawing northern wetlands.
Scientists have assumed that wetland methane release is largest in the tropics, said Turetsky.
“But our analyses show that northern fens, such as those created when permafrost thaws, can have emissions comparable to warm sites in the tropics, despite their cold temperatures. That’s very important when it comes to scaling methane release at a global scale.”
The study calls for better methods of detecting different types of wetlands and methane release rates between flooded and drained areas.
Fens are the most common type of wetland in Canada, but we lack basic scientific approaches for mapping fens using remote sensing products, she said.
“Not only are fens one of the strongest sources of wetland greenhouse gases, but we also know that Canadian forests and tundra underlain by permafrost are thawing and creating these kinds of high methane-producing ecosystems.”
Most methane studies focus on measurements at a single site, said co-author Narasinha Shurpali, University of Eastern Finland. “Our synthesis of data from a large number of observation points across the globe is unique and serves an important need.”
The team showed that small temperature changes can release much more methane from wetland soils to the atmosphere. But whether climate change will ramp up methane emissions will depend on soil moisture, said Turetsky.
Under warmer and wetter conditions, much more of the gas will be emitted. If wetland soils dry out from evaporation or human drainage, emissions will fall – but not without other problems.
In earlier studies, Turetsky found drying peatlands can spark more wildfires.
Another study co-author, Kim Wickland, United States Geological Survey, said, “This study provides important data for better accounting of how methane emissions change after wetland drainage and flooding.”
Methane emissions vary between natural and disturbed or managed wetlands, says Wickland, who has helped the IPCC improve methods for calculating greenhouse gas emissions from managed wetlands.
Turetsky holds a Canada Research Chair in Integrative Ecology. She and her students examine how ecosystems regulate climate in field sites in Canada and Alaska.
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Er, well if there has been increased greenhouse gases, which there has, and if they cause increase in termperature, then why has the temperature stayed the same?
Perhaos the answer is because the asymptote has been reached due to saturation. Further addition of greenhouse gases will not produce further increases in temperature.
“Under warmer and wetter conditions, much more of the gas (methane) will be emitted.”
OK, the study says wet wetlands are bad.
“In earlier studies, Turetsky found drying peatlands can spark more wildfires.”
OK, previous studies said dry wetlands are bad.
So… it’s all bad no matter what. Well, this’ll pass peer review easily…
“…If wetland soils dry out from evaporation or human drainage, emissions will fall – but not without other problems.”
Other problems? They are dead right. Wetlands are relatively cool and chuck out much less heat than dry land. It is beyond annoying that the only ‘currency’ in this sorry debate about climate is the affect of ‘greenhouse’ gases. It is looking like a dreadful distraction.
I found this:
“A 2006 UN FAO report reported that livestock generate more greenhouse gases as measured in CO2 equivalents than the entire transportation sector. Livestock accounts for 9 percent of anthropogenic CO2, 65 percent of anthropogenic nitrous oxide and 37 percent of anthropogenic methane. A senior UN official and co-author of the report, Henning Steinfeld, said “Livestock are one of the most significant contributors to today’s most serious environmental problems.”
http://en.wikipedia.org/wiki/Atmospheric_methane
Interesting to note that they equate cow “emissions” as “anthropogenic” (‘man-made’).
I wonder what my fellow ruminants think of that…
The methane released from this Professor’s backside contains more intelligence than written in his words. He clearly has no understanding of engineering science or science data. Yes, bogs and rotting vegetation (including human rubbish tips) do emit methane but this has no effect (repeat no effect) on the atmosphere. Please look at my post http://cementafriend.wordpress.com/2011/10/14/methane-good-or-bad/ and reply if you can prove that the facts given there are wrong. – methane absorbs less radiant energy than does CO2. Quoting some green inspired publications is not proof. Measurement is the only proof.
The IPCC ‘preparing to examine’ something in and of itself is far more frightening than snail farts.
You can tell from the title of the journal that it is “high” quality.
Tell him/her/it to lay off the brussel sprouts.
It’s too damn cold in Boston today!
Not that that means anything, which it would . . . if it was too damn hot.
I cannot get behind a movement to drain wetlands. Sorry.
Yes, they’re going to “manage” the world’s ecosystems; wonderful. Just as they’ve managed the world’s economies into a shambles, and we have evidence of how much damage has been caused by previous management of ecosystems, such as our forests.
These damned people need to learn to just keep their hands to themselves and stop being so arrogant as to think humans can manage natural systems (including the economy). But alas, I don’t see that happening anytime soon.
May as well drain all the swamps. Swamp People and Gator Boys are so passe’. The government has a plan to tax cow farts to save us, but as yet I fail to see a way to tax termites. Give’em time.
I thought the GHG contribution by methane was largely irrelevant in the presence of water vapor because the spectral absorption qualities of methane overlay that for water vapor which therefore swamps methane’s affect?
So, this means Ducks Unlimited is responsible for most modern warming then?
Clearly we need a Swamp Tax. Since the tax code is a bit of a swamp already, it ought to be easy to implement.
As I understand it methane forms less than 2 molecules per million molecules of the atmosphere. What is the fuss about?
Finally! I can drain that darn wetland in my back yard. And when town comes complaining, I’ll claim that I’m saving the world and point them to gold standard of science – peer reviewed article that is saying how evil those things are.
Yea!
“Drain the wetlands”
Don’t forget to drain the rice fields.
With global temperatures rising as a result of climate change, the emission of methane — which traps about 25 times more of the Sun’s heat than carbon dioxide — will play a greater part in the global carbon budget than it does now, says Butenhoff. Based on the temperature-increase projections of the Intergovernmental Panel on Climate Change, he and his colleagues estimate that methane emission from paddies in China could go up by a further 2.5 million tonnes by 2100. “This is a massive amount,” he says. “We can’t even get an estimate for India because the [methane] emission would be so high it’s off the chart.”
Adam (Apr 29 5:14 am ) gets it in one: “if there has been increased greenhouse gases, which there has, and if they cause increase in termperature, then why has the temperature stayed the same?“. If this latest paper on methane is correct, then it demonstrates that climate sensitivity to GHGs is lower than previously thought.
Even if you buy into recent surface temperature rise being as a result of increased greenhouse gasses, methane is an irrelevant gas in the theoretical causes.
Methane (CH4) has only two narrow absorption bands at 3.3 microns and 7.5 microns in the radiation spectrum. Theoretically, CH4 is 20 times more effective an absorber than CO2 – in those bands. However, CH4 is only 0.00017% (1.7 parts per million) of the atmosphere. Moreover, both of its bands occur at wavelengths where H2O is already absorbing virtually all energy. Because water vapor is much more plentiful in the atmosphere than methane (or any other GHG), H2O absorbs vastly more energy and is by far the most important greenhouse gas. On any given day, H2O is a percent or two of the atmosphere (1.0-2.0% or 5,882 to 11,764 times as prevalent as methane in the atmosphere); we call that humidity. Hence, any radiation that CH4 might absorb has already been absorbed by H2O in the only radiation bands methane absorbs energy. Once the energy in a band of the spectrum has been sucked dry, no additional absorptive gas can absorb more. Painting a black window another coat will not keep out more light. In other words, the ratio of the percentages of water to methane is such that the effects of CH4 are completely masked by H2O because the absorption of infrared energy in the bands of the spectrum affected by methane has already been saturated by H2O absorption. The amount of CH4 would have to increase 100-fold to make it comparable to H2O.
From a recent WUWT article—
http://wattsupwiththat.com/2014/04/11/methane-the-irrelevant-greenhouse-gas/
Canada (the country-of-origin of this report) has a clear interest in ‘draining wetlands’. As do Alaska, Siberia, Russia and Scandinavia.
Preservationists want to declare the Boreal or Taiga zone (much of which is minimally-developed) off-limits. It’s the new ‘Amazon Rainforest’. ‘Set aside’, er, protect the whole thing. And our established geopolitical players in the temperate zone to the south can readily do the math … which shows that a better-developed higher-latitudes zone would become a serious competitor.
Most “draining” etc has historically been about agriculture. Forestry could also benefit dramatically in the north, by modifying the very prevalent & extensive adverse ‘wetlands’ chemistry. Both of these (ag & timber) are quite-sensitive economic & political areas.
Canada & Russia et al have long had a belly-full of being on the short & crappy end of the ‘gratuituous Preservationism’ stick. They are reliable allies of the WUWT orientation & philosophy … and we see this rather often, in their formal science-work.
This will be a topic worth watching.
On a related note, how much methane is NOT being released right now because of all the wetlands humans already drained??? In my rough way I attempted to answer this before, and certainly dont take my word for it, but it appeared to me the methane we release now would have been dwarfed by those wetlands we already drained.