Outline
Carbon dioxide is added to the atmosphere by:
decay of vegetation, respiration (exhalations of animal
life), combustion of fossil fuels, deforestation
Carbon dioxide is removed from the atmosphere by:
photosynthesis, oceans (hold 50 times more CO2 than
the atmosphere)
Carbon dioxide concentration is increasing:
has increased about 20% (from 315 ppm to 370 ppm)
between 1958, when direct measurements were
started (Mauna Loa, Hawaii), and the present day.
Concentration measurements prior to 1958 come from
ice cores. Ice core data show concentration
was about 280 ppm up until the early 1800s then
started to increase.
concentration might reach 500 ppm by 2100.
Carbon dioxide is a greenhouse gas:
increasing amounts of CO2 and other greenhouse gases
[methane, nitrous oxide, CFCs, and water
vapor] may cause a 1.4 to 5.8 C increase in global
average surface air temperature.
Report
Carbon dioxide is added to the atmosphere by
respiration (we breathe in oxygen and breath out carbon
dioxide), decay, combustion of fossil fuels, and deforestation.
Living plants remove CO2 from the air
during photosynthesis and add oxygen to the air (that's why deforestation adds CO2 to
the air). CO2
also dissolves in the world's oceans; they contain about 50 times as
much CO2 as the atmosphere.
There is a lot less CO2 in the atmosphere than
nitrogen or oxygen, but the CO2 concentration is
increasing. In 1958, when measurements of atmospheric CO2 were
started at the Mauna Loa
Observatory in Hawaii, the concentration was 315 ppm. The concentration is
now closer to 370 ppm.
CO2 is a greenhouse gas (together with methane, nitrous oxide, and
chlorofluorocarbons). There is
concern that increasing concentrations of greenhouse gases could cause
global average surface air
temperatures to increase. It has been possible to determine
atmospheric CO2 concentrations prior to
1958 by analyzing ice cores from Greenland and Antarctica. The
CO2 concentration was fairly constant
at 280 ppm up until the early 1800s, when it started to increase.
Predictions are that CO2 concentrations
may increase to 500 ppm which may cause a 1.4 to 5.8 C of
warming. This could have a lot of
undesirable effects on our
weather.
Grading
A total of 3.5 content pts and 2.5 writing quality pts were available
on this report. This particular report earned 3 content points
and 2 writing quality points for a total of 5 pts. The grader
commented on the 3 items highlighted in red above. Deforestation
adds CO2 to the atmosphere because dead plants decay, ppm stands
for parts per million and are units of concentration, the report could
include a specific example or two of undesirable effects of global
warming on the weather.