photosinthisis in the process in plants of taking co2 and water to
produce oxygen and glucose. there for it is important to global warming
because if we cut down the trees the co2 emisions will increase and
damage the o-zone layer.

CO2 does not damage the ozone layer. Anyway the real problem about
global warming is the use of fossil fuels more than the cutting of
trees. To prevent global warming there should be more trees than
possible on earth.

wrote in news:1127922544.679386.3240
@g43g2000cwa.googlegroups.com:

CO2 does not damage the ozone layer. Anyway the real problem about
global warming is the use of fossil fuels more than the cutting of
trees. To prevent global warming there should be more trees than
possible on earth.



We may not be able to prevent global warming. Global warming may not
be caused exclusively by CO2 emissions, it may be caused by an
increase in solar temperatures. If that is the case, we need only
look to the history of this planet to determine that life will
survive. All of the carbon that is currently locked up in coal and
oil was once available to plants as CO2 in the atmosphere, and
during those times, plant life flourished. Flourished sufficiently
for trees to lay down those coal beds, for algae to form oil
deposits. The result of increasing CO2 levels will result in
increased plant growth. Carbon dioxide availability is a limiting
factor in the growth of many plants, many desert plants go to
extraordinary means to capture as much CO2 and lose as little water
as possible.

CO2 levels from burning fossil fuels don't explain why this planet
occasionally sees ice ages and warmer periods.

There is no question that global temperatures have increased
recently, but there are questions about a few things, such as: what
causes it; and is it a bad thing?

Sean

I agree. I think that it should be pointed that direct measurements of
climate variables has only been taken since the last two centuries. The
rest are indirect calculations from fossil evidences and so. So could
we say that a few degrees increment in last decades is an aberration?
what are two centuries in geologic time?
I only pointed CO2 emissions because they are possibly the main factor
due to human activity but not because human activity is the main factor
in global warming.
I am sorry if I was too strict in my first assertion.
Anyway, it is all right to think that reducing CO2 emmisions we will
mend something about that. It should be done at any moment, why not now
and by that reason?

Even if one assumes that the increase in atmospheric carbon dioxide
caused by human activities has no effect on global warming, it is a
symptom of rapid destruction of rainforests and excessive and
inefficient use of fossil fuels. Many negative aspects of fossil fuel
use are quite clear including acid rain, much of several other types of
air pollution (ozone, peroxyacetyl nitrate or PAN) and its negative
effects on human health and the environment, coal strip mining and its
associated water pollution and habitat destruction, and the
environmental damage caused by oil spills and oil drilling.

The idea that increases in atmospheric carbon dioxide will increase
plant growth is not always supported by recent research. That is not
surprising given that under natural conditions plant growth is often
limited by factors other than low carbon dioxide levels, such as lack
of water and lack of mineral nutrients. Research has also shown that
even when higher carbon dioxide levels increase crop growth, the crops
may have less nutritional value.

David R. Hershey

References

Carbon dioxide fertilization is neither boon nor bust
http://www.newswise.com/articles/view/503175/

A shrinking sink? Carbon fertilization may be flimsy weapon against
warming
http://www.innovations-report.com/ht...ort-25846.html

Rising carbon dioxide could make crops less nutritious
http://www.scidev.net/News/index.cfm...9&language =1