In article lgate.org, says...


I taped the OU programmes from last night; running back quickly through
them just now, I came across this little gem:

There is apparently, a planet wide lack of carbon dioxide in the
atmosphere according to one ecologist on the last programme "The Big
Picture".

Talking about satellite analysis: different spectra of different
seasons, overlain, show that plant growth seems to be inhibited by the
lack of CO2 in their growing seasons. This is especially marked in the
tropics.

Not likely. The CO2 levels in the atmosphere are rather well mixed around
the globe, except in areas downwind of major sources, such as cities.

However the tropical models are already at a maximum due to all the
available sunlight being used. The most substantial increase in growth
appears to be along the forested regions of the northern hemisphere.

More northerly climes are inhibited by the cold.

In the Sahel, where a higher concentration of carbon dioxide would help
faster growth -and the accompanying better water retention/recycling;
there is a striking benefit in greater concentrations of CO2 in the
models shown.

Normalised Difference Vegetation Index -but you might get more hits with
: Normalized Difference Vegetation Index e.g.:

http://earthobservatory.nasa.gov/Lib...ingVegetation/

The idea that increasing CO2 will benefit plants has been around for a while.
The expectation was that increasing CO2 will lead to increased plant growth.
In most cases, plant growth is limited by the lack of some nutrient other
than CO2. In the case of a greenhouse or similar open air experiments,
increasing CO2 can promote plant biomass, however, that's under ideal
conditions in which extra water and fertilizer is provided to the plants.
Longer term experiments in open environments indicate that increasing CO2
alone will briefly cause an increase in plant growth, after which the soil
becomes depleted in other nutrients and the growth rates decline, AIUI.
In other words, natural ecosystems might not fair well, while agriculture
might be able to benefit thru the use of fertilizers and irrigation, (both
of which now depend on massive use of fossil fuels, BTW).

The drought prone/desert areas of the world occur in areas where the
atmospheric circulation produces subsiding air, which tends to be dry,
thus little rain falls. Increasing CO2 may change the location of these
dry belts, but they are likely to continue to exist. Some models have
pointed to an increased incidence of drought in the Great Plains of the
U.S. as a result of Global Warming resulting from increased CO2.

--
Eric Swanson --- E-mail address: e_swanson(at)skybest.com :-)
--------------------------------------------------------------