Wetlands to Slow or Grow Global Warming?

  • John Pastor is trying to figure out how climate change will affect bogs and fens like this one. (Photo by Bob Kelleher)

In northern Minnesota, a researcher says wetlands like bogs could be key to how fast the climate changes worldwide. And the areas like the upper United States and Canada in the bull’s eye for rapidly changing temperatures and rainfall. The GLRC’s Bob Kelleher reports:

Transcript

In northern Minnesota, a researcher says wetlands like bogs could be key to how fast the
climate changes worldwide. And the areas like the upper United States and Canada in the
bull’s eye for rapidly changing temperatures and rainfall. The GLRC’s Bob Kelleher
has more:


What have wetlands, like fens and bogs, got to do with global warming? John Pastor says,
plenty.


Pastor is a professor and researcher with the Natural Resources Research Institute of the
University of Minnesota-Duluth. When Pastor straps on his hip waders, he goes where
almost no one else dares to go: into northern Minnesota’s fens, where water can be
several feet deep, and onto the bogs, where the mass of plant material is so thick it floats
on standing water.


A seven year-long study has revealed that fens and bogs can either help slow global
warming, or accelerate it. Pastor says all cards are off the table if temperatures keep
rising:


“The one problem in science that has the most ramifications throughout all of science – it’s
global warming.”


We’re in a swamp north of Duluth, Minnesota. Actually, it’s a fen, and it borders some
higher landscape nearby that’s a bog. What fens and bogs have in common is water and
peat, the not quite decomposed stuff left over when plants die. Pastor says peat lands are
one of the world’s significant bank accounts for carbon. They keep carbon out of the
atmosphere.


“Peat lands cover only 3% of the earth’s surface, but they contain 30% of all the carbon
that’s in all the soil in the world, locked in that partially decomposed organic matter, that
peat.”


Minnesota has vast peat lands that have been storing carbon for 10,000 years, but even
the size of Minnesota’s peat lands pales compared to those further north – around
Canada’s Hudson Bay, or in the Russian republics – all regions Pastor says that are facing
higher temperatures.


“All of the global climate models, one thing they all agree on, is that the greatest amount
of warming will occur in areas from Minnesota northward, and then inland – mid-
continent areas. So here we are. We’re sitting right now, right in the bullseye of the
greatest amount of warming that will happen on the face of the earth.”


This is the question: Will higher temperatures help trap more carbon in bogs, or force
more carbon into the atmosphere?


In this bog, Pastor’s been trying to figure out how warmer weather will affect bogs and
fens, and, in turn, what role the wetlands will play in global change. One thing he’s
found: the results depend largely on the water table, and that’s going to depend on
rainfall.


In some combinations, say with additional heat and additional rainfall, bogs could thrive,
trapping more carbon. That would be good. In other conditions, say with more heat but
less rainfall, bogs and fens could die and decompose, releasing even more carbon into the
atmosphere. That, Pastor says, would be bad:


“Now we have kind of a double whammy. Not only are we putting carbon dioxide from
fossil fuel into the atmosphere, the warning from that could cause the carbon from the
peat land also to go into the atmosphere and accelerate the warming.”


Predicting an outcome becomes mind numbing. Pastor’s working with new mathematical
theory to try to determine at what point global warming has gone too far.


“And so what seems to be happening is the temperatures of the earth have crossed some
kind of a threshold, where all the sudden, before that they crossed that threshold, the old
earth that we grew up with was stable. Now, it’s becoming very unstable, and ice sheets
are collapsing, birds and plants are migrating – everything’s happening very, very
quickly. And we’re going to enter into a new kind of earth that has a different kind of
stability – a different stable endpoint.”


Pastor says there’s no more complicated problem in all of science than global warming,
and no more important problem. Global warming, he says, changes everything, from the
forests to the wetlands. Pastor’s hoping the new mathematical models will provide more
definitive answers in time to do something about the outcome.


For the GLRC, I’m Bob Kelleher.

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