The Global Carbon Cycle
Why It's Important
Atmospheric carbon dioxide comes from a variety of sources,
some of them natural, but increasingly from human activities. Carbon
dioxide and other gases (together, known as "greenhouse" gases)
in the atmosphere absorb radiation emitted from the Earth, trapping heat
in the atmosphere and contributing to the warming of Earth's atmosphere.
Although a greenhouse also works by trapping energy from the sun, the
physical processes are different (See this university site
for a more
detailed explanation). NOAA researchers are very interested
in the sources and storage systems of many "greenhouse gases."
In the geological history of the Earth, carbon has been
cycling among large reservoirs in the land (including plants and fossil
fuels), oceans, and the atmosphere. This natural cycling of CO2 usually
takes millions of years to move large amounts from one system to another. Now
we are looking at these changes occurring in centuries or even decades.
NOAA Researchers joined an international team of
scientists to measure the carbon dixoide stored in the world's oceans.
(larger image)Since the Industrial Revolution in the 19th century, carbon
dioxide in the atmosphere has risen by 30 percent. This follows the increase
in burning of fossil fuels that began with the rise of industry and transportation.
NOAA's Goals
One of NOAA's
major mission goals is
to "understand climate variability and change to enhance society's
ability to plan and respond." This is why NOAA scientists are examining
the entire global carbon cycle - including the Earth's atmosphere, fossil
fuels, the oceans, and terrestrial ecosystems -- to better understand
how the carbon cycle works and to help us predict how it will act and
react in the future.
The CCGG Cooperative Air Sampling Network includes
surface, observatory, aircraft and tower atmospheric measurements
(larger
image)
NOAA Research has been studying various aspects of the
carbon cycle for a number of years. Because the ocean plays an important
role in regulating the amount of CO
2 in the atmosphere and regulating
climate variability, NOAA's ocean-oriented labs are involved in this
issue. At NOAA's
Pacific Marine Environmental Laboratory Carbon
Dioxide Program , located in Seattle, Washington, scientists conduct ocean carbon cycle research
from ships and moorings in all of the major ocean basins in collaboration
with NOAA's
Atlantic
Oceanographic and Meteorological Laboratory's CO2 Program.
A recent study looked at distribution
and impacts of carbon dioxide in the world's oceans. This study is
one example of the critical role the oceans play in removing anthropogenic
(derived from human activities) carbon dioxide from the atmosphere.
Possibly the best known graph in carbon cycle science is the long, continuous record of carbon dixoide measurements at Mauna Loa, Hawaii.
(larger image)NOAA's Climate Program Office supports research to improve
our ability to predict
the fate of human-made CO2 and how much will
end up in the atmosphere in the future using
atmospheric and oceanic global observations, process-oriented field studies
and modeling. Its priorities are to study the sources of CO2 and
its sinks, that is, reservoirs for CO2 outside
the atmosphere, such as large forests.
ESRL's global monitoring
division in Boulder, Colorado,
maintains a global air sampling program that is useful in telling researchers where
carbon dioxide is coming from, and where it is going. These careful,
continuous and consistent
measurements all over the globe are
key to monitoring levels of atmospheric carbon dioxide globally, serving
as benchmark measurements for climate process studies and models.
The keystone
site of NOAA's monitoring network is on the
flank of the Mauna Loa volcano in Hawaii, where
continuous CO2 measurements have been taken since 1957, resulting
in one of
the best recognized graphs in science today. The
Mauna Loa observations were begun by a pioneer
in carbon cycle science, the late Dr. Charles "Dave" Keeling.
These is a story behind every one of the sampling sites
managed by NOAA. One story tells about the retired
school teacher in Mongolia who collects air samples for NOAA's network.
Recognizing the integrated nature of the carbon cycle,
six federal agencies (DOE, NASA, NSF, NOAA, USDA, and USGS) are coordinating
their individual carbon cycle research programs into a partnership, the
Carbon Science Cycle Program,
to address common research goals outlined in A
U.S. Carbon Cycle Science Plan.
NOAA Research Programs that study the Global Carbon Cycle
Climate Program Office (CPO)
Earth
System Research Laboratory (ESRL)
Pacific
Marine Environmental Laboratory (PMEL)
Atlantic
Oceanographic and Meteorological Laboratory (AOML)
