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>>Theresa Bierer: Global warming affects all of us, the more we learn about the nuts and
bolts about global warming the better chance we have of doing something about it. On this
next Inside NAU science segment professor Bruce Hungate conducts research on the peaks
on global warming. >>Bruce Hungate: I find ecology fascinating,
microbiology especially really interesting how soil microorganisms control nutrient cycles
and how that affects how plants grow. And it turns out that those same microorganisms
actually have the potential to impact climate and that just blows me away, these little
tiny cells in the soil having an effect on the global scale, I just think that's cool.
The Earth's getting warmer; the intergovernmental panel on climate change that synthesizes all
this climate change research says that most of that warming we've seen is due to human
activities. We want to be able to say how much more warming is going to happen and one
of the missing pieces is how will ecosystems respond to climate warming? One of the ways
they can respond is by producing more of the very gases that warm the earth. So this research
is really focused on that question, we're using the elevation gradient right here in
our backyard in Flagstaff. So we have five field stations along that gradient, they start
at the top in the Mixed-Conifer Forest at the Ponderosa, to the Pinyon-Juniper Woodlands
to the high desert grassland to the Great Basin Desert. To simulate global warming what
we're doing is we're taking a micro ecosystem, a piece of the ecosystem, the soil, the plants,
all together from one life zone and we're moving them down the gradient one step. And
what that does is it simulates roughly the warming projected for the next 5,200 years.
It's a really nice way to manipulate warming for a couple of reasons; you're warming both
the air and the soil that's realistic and it's very easy to maintain. We're getting
ready now to measure the production and consumption of carbon dioxide, methane, and nitrous oxide,
from these plots. >>James Brown: This is the chamber that we
use, it's got an attachment at the top for the canisters and so we place it over the
core, make sure we have an airtight seal and we take one of the canisters that immediately
sucks up 100CC sample. Then we use a syringe to pull an extra 60ccs inject it into the
canister to over pressurize the canister so that we can run it on the GC back at the lab.
>>Hungate: Carbon dioxide is the most important greenhouse gas that humans are producing and
causing to increase in the atmosphere but methane and nitrous oxide are the next two
important ones. >>Student: We're going to take a sample of
the trace gas that is inside this cylinder and we're going to inject it into our pre-concentration
unit to prepare it for the Gas Chromatigraph, which is also referred to as a GC. The Gas
Chromatigraph actually separates the different gasses that are contained inside of the sample
and then it allows for a measurement to be made on a single gas and in particular using
this instrument we're looking at nitrous oxide. >>Hungate: Nitrous oxide is also laughing
gas, right what you get in the dentist office and it's increasing in the atmosphere, not
enough to make the world a happier places but it is enough to contribute to the warming.
Nitrous oxide, molecule per molecule is about 300 times more effective at trapping heat
than carbon dioxide so it's an important greenhouse gas too. One of the things we hope is that
by doing experiments like this, by looking into the details of one community and one
ecosystem, we can take those responses and distill from them some general principles
that tell us about how ecosystems will respond to climate change. The plants we see in these
tiny little plots right here are actually very relevant to what we expect in terms of
how the world works 50 to 100 years from now when our climate will presumably be warmer.
>>Ellen Grabarek: Hi I'm Ellen Grabarek, the project director for Del E. Webb Dental Outreach
Program, you're watching Inside NAU.