Last month (August, 2011), scientists from Lawrence
Berkeley National Laboratory (Berkeley Lab) and several other U.S. Department
of Energy national laboratories traveled to two small Alaskan towns—tiny dots
amid the vastness of the tundra, and perfect places to observe Earth at a
crossroads.
Near Council, on the Seward
Peninsula, the permafrost is already thinning due to climate
change. Hundreds of miles north near Barrow, the northernmost town in the U.S., the
permafrost is frozen thick, for now.
What happens here in the years ahead could have a
far wider impact than an altered Arctic landscape and a different way of life
for the people who call it home.
Trapped within the permafrost are billions of tons
of carbon deposited by plants over the millennia. The carbon might stay put. Or
it might enter the atmosphere in the coming decades as the permafrost thaws,
further accelerating climate change.
No one knows how this story will unfold. The Arctic
ecosystem is incredibly complex and in many ways poorly understood.
Because of these uncertainties and what’s at stake,
the scientists are proposing The Next-Generation Ecosystem Experiment. The
project is designed to answer one of the most urgent questions facing
researchers today: How will a changing climate affect the Arctic,
and how will this in turn affect the planet’s climate?
Berkeley Lab scientists contribute to many aspects
of the proposed project, which is led by Oak Ridge National Laboratory’s Stan
Wullschleger. The collaboration also includes researchers from Los Alamos
National Laboratory, led by Cathy Wilson; the University
of Alaska at Fairbanks, led by Larry Hinzman; and
Brookhaven National Laboratory, led by Alistair Rogers.
“Our recent trip to Alaska allowed us to begin
laying the foundation for the Next Generation Ecosystem Experiment, which will
dramatically improve our understanding of how degrading Arctic permafrost
affects feedbacks between ecosystems and the climate,” says Susan Hubbard, a
geophysicist in Berkeley Lab’s Earth Sciences Division who leads Berkeley Lab’s
participation in the collaboration.
The Next Generation Ecosystem Experiment’s
expansiveness sets it apart from other efforts to study the relationship
between the Arctic ecosystem and climate. Over the course of several years, the
scientists will study interactions between plants, soil, microbes, water, and
air. They’ll measure how degrading permafrost affects carbon, methane, and
nitrogen cycles. They’ll track the flow of energy. They’ll analyze processes
that occur among microscopic molecules as well as regions that span hundreds of
square kilometers. And they’ll conduct research in the field as well as in
state-of-the-art facilities thousands of miles away.
All of this research will enable scientists to
develop powerful computer models that predict how the Arctic
will change in the decades and centuries to come.
To start the process, scientists from the
collaboration met with members of local communities and scouted potential
research sites during the August trip.
Once the experiment begins, Berkeley Lab scientists
will lead two components of the proposed project and will be involved in
several other aspects. Hubbard will lead the effort to use geophysical methods
to characterize the sites, which will be near Council, Barrow, and possibly
other areas. Her group will develop ways to remotely monitor permafrost degradation
and associated hydrological and biogeochemical processes that lead to
greenhouse gas production.
Soil scientist Margaret Torn, another member of
Berkeley Lab’s Earth Sciences Division who traveled to Alaska, will lead the effort to quantify the
land’s energy balance. Her group will explore how permafrost degradation
affects albedo, which is the reflection of solar radiation back into space. Her
group will also study the flow of energy from the surface to the subsurface, a
phenomenon that speeds up permafrost thaw.
Other Berkeley Lab scientists will conduct detailed
analyses of the microbial communities that live in permafrost and quantify
their role in the breakdown of organic soil carbon. And still others will help
develop computer models that simulate how microbial soil processes cause
degrading permafrost to emit greenhouse gasses.
“Through laboratory, field, and numerical research,
the NGEE team will be able to quantify and incorporate complex
ecosystem-climate processes into computer models,” says Wullschleger, a plant
physiologist with Oak Ridge National Laboratory. “The breadth of expertise that
this multi-disciplinary team brings to the NGEE project provides an opportunity
to significantly advance our understanding and prediction of the Earth’s
climate system.”
The proposed project is being developed under the
auspices of the Biological and Environmental Research program office, which is
within the U.S. Department of Energy’s Office of Science.
