Carbon
dioxide in the atmosphere
The level of carbon dioxide (CO2) in the
atmosphere has risen by as much as 40% since the Industrial Revolution.
The graph above shows the dramatic increase
of CO2 in the atmosphere since 1960, as measured at the Mauna Loa Observatory in Hawaii.
CO2 in the atmosphere, along with other
gases like methane, nitrous oxide and water vapour, acts as a greenhouse gas, trapping
much of the sun’s reflected energy before it returns out to space. The effect
is to increase the surface temperature of our planet – global warming. (Here’s
a link to an excellent explanation of the greenhouse effect by the Department of the Environment and Energy).
Photosynthesis
Trees, (in fact all plants), absorb CO2
from the atmosphere and through photosynthesis convert it to nutrient, glucose,
for the tree to grow. There are are numerous websites that explain
photosynthesis in more or less detail. Put very simply;
carbon dioxide + water (+ sunlight) = glucose
+ oxygen.
Australia’s native forests, about 147
million hectares, hold in store (or sequester) about 10.5 billion tonnes of
carbon which translates to about 38.5 billion tonnes of carbon dioxide, (Australia’s Chief Scientist)
Saving the planet and looking beautiful |
Every
little bit counts
When we drive our cars or switch on the
television, etc, we produce carbon. Every Australian person produces about 8
tonne of carbon a year. To offset that much carbon, each person would need to
plant more than 20 eucalypts a year for many years. This means we should be
doing as much as we possibly can to preserve our existing mature trees and for
every one we lose, replacing it with at least 20 more young seedlings.
An
Example
Before - probably holding 46 tonne of CO2 |
Not anymore |
The giant Mountain Grey Gum at the southern
end of Oddy St was cut down in August this year. The tree was strong and
healthy, and measured 1.4m diam and 30m tall. Using forestry standard
calculations for eucalypts, this tree was sequestering more than 45 tonnes of
CO2.
Note
You can calculate your own greenhouse gas
emission at the EPA Vic website.
The main sources of carbon dioxide detailed
at What’s Your Impact.
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