Trees reduce the greenhouse effect by
absorbing carbon dioxide (CO2), one of the principal ‘greenhouse gases’, and by
shading our homes and offices.
During photosynthesis, trees absorb CO2
from the air and use it to help make other compounds essential for plant growth
and oxygen is released back into the atmosphere.
By shading our homes and offices, trees
reduce the amount of electricity needed for air conditioning. Most of our
electricity is produced by burning coal, which produces carbon dioxide that is
released into the atmosphere. A shady tree is both directly and indirectly reducing
the amount of CO2 in the atmosphere.
Carbon dioxide however, is not the
principal air borne health risk of urban areas. CO2 is a problem gas in terms
of climate change, but more health problems to residents are due to nitrous
oxides and particulates from vehicle exhausts and factory emissions.
Nitrous oxides and particulates in the air
can have serious health effects especially for children and the elderly, including
respiratory and cardiac problems and even premature mortality.
Softening building lines, absorbing industrial emissions, mitigating noise |
Numerous worldwide studies have shown that
well planted urban forests can filter large amounts of particulate matter from
the air. A recent study indicated that the urban trees of London removed
between 800 and 2000 tonnes of particulates from the air each year. Research in
the United States concluded that the trees of New York saved an average of
eight lives per year by absorbing particulates.
The nitrous oxides from car exhausts and
other gases in the air are removed when the leaves of a tree absorb the air
through their pores. In 2008, a team of researchers at Purdue University in
Indiana, showed that trees were capable of absorbing the dangerous nitrous
oxides and converting them into useful amino acids for other plants to use.
Acid rain is a phenomenon caused by the
oxides of sulphur and nitrogen reacting with the moisture in the air to produce
rain drops that are acidic. When a tree absorbs nitrous oxides from the air it
is helping to ameliorate the corrosive effect of acid rain in some regions.
Not just beautiful! |
Trees can make urban areas healthier places
in which to live.
No comments:
Post a Comment