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http://wwwsrv.cmdl.noaa.gov/ccgg/figures/co2obs.gif
http://wwwsrv.cmdl.noaa.gov/ccgg/figures/co2obs.gif |
Global warming is one of the most important issues in
environmental science today. Greenhouse gases are a primary
contributor to global warming. Sunlight reaching the earth is
reflected back to space as heat, but some of this heat is trapped by
the greenhouse gases, hence the "greeenhouse effect." Many
scientific models predict an increase in global temperatures due to an
increase in these gases in the atmosphere. Methane, water vapor,
ozone, nitrogen oxide, and carbon dioxide are all greenhouse gases,
with the last being the most important. Human-produced sources of
Carbon dioxide include the burning of fossil fuels and deforestation.
Carbon dioxide levels in the atmosphere are also affected by
photosynthesis. Because phytoplankton are responsible for
approximately 50% of the Earth’s photosynthesis, they may play an
important role in regulating atmospheric Carbon dioxide. In addition,
Carbon dioxide is exchanged between the atmosphere and the ocean. The
ocean itself acts as a sink for carbon as marine organisms die and
settle out of the water column to the ocean floor.
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