just a thought

[k]

Many serious scientists have already suggested the net change in CO2 could
actually benefit the world, but this takes a longer view of the processes
involved:


The role of plants in the depletion of the atmosphere.

Plants evolved a long time ago on this planet, long before almost everything
else and they primarily use the sun as a source of energy by binding the
carbon dioxide (CO2) in the air in their metabolic processes and making food
for themselves. when they die, they leave wood behind - and wood is rich in
carbon.

The method of binding CO2 using the sun is known to all school kids as
photosynthesis, but what we're often not taught is that there are three
methods of photosynthesizing food, the main two processes are known to
botanists and biochemists as C3 and C4, the other is CAM . C3 plants form
about 97% of all plants on Earth and were there at the dawn of time and
their process has not changed. C4 are relatively newer and probably evolved
to cope with the diminishing levels of CO2 and form about 3% of plant
species. There are very CAM plants and most resemble cactus. Almost all the
plants you can think of including all our food crops are C3 plants.
Back at the time when plants first evolved to scavenge food from the air
using sunlight there was far, far higher levels of CO2 in the air and as
these levels have dropped, the C3 plants have had to cope by using more
water. They are effectively starving as the CO2 levels lower, and using more
water allows them to survive.

So where did all the CO2 go? We again are taught in school that normally
when plants die, bacteria consume the remains releasing the CO2 and methane
which in time also breaks down to CO2, thus replenishing the atmosphere.
However, eons back in times when CO2 was plentiful the plants grew
enormously fast and large. Their method of gathering food worked well, but
as often happens when a resource is plundered without concern for the future
there are unforseen consequences. The problem for the plants was that they
grew so fast and so dense in this time of a CO2 enriched atmosphere that
there simply wasn't time enough for the bacteria to break down the masses of
wood and so it collected and in time compressed, solidified and fossilized
to form what we now call coal. There are trillions of tons of coal
underground, even in the Arctic.

CO2 is also absorbed by the ocean where it converts to carbonic acid, then
carbonates, then eventually calcium carbonate or limestone. The shorelines
of the world are lined with marble, limestone and sandstone which are locked
up forms of carbon dioxide. Again, trillions of tons of carbon is locked in
limestone.

So how big a deal is it for these C3 plants to cope today with our low
levels of CO2? Well we now have an atmospheric concentration of CO2 of
around 350 parts per million (or ppm). That's not a lot, considering plants
evolved when it was over 3000 ppm. In fact growers who use greenhouses
often increase their yields dramatically by pumping carbon dioxide food in
for the plants in the order of 1000 to 1500 ppm. This doubles the plant
growth and can cut the amount of water the plants need by as much as 90%.
This is a huge benefit to growers both in saving water and in having twice
as much food produced by plants from the same amount of area. They can
actually increase the amount used to 10,000 ppm but it becomes more
expensive and the return is proportionally not as great. However, it is
clear that reducing the fertilizer and water required by simply increasing
the CO2 available to the plants is a relatively cheap way of letting the
plants grow in an environment closer to their optimum.

What happens if the CO2 levels continue to fall? The old, dominant C3 plants
could in time be replaced by the more drought tolerant C4 and CAM plants and
due to their efficiency these plants will draw even more CO2, their food,
from the air. These plants are less reliant on water so they cannot be as
controlled by such environmental conditions as drought. As more efficient
consumers they are far more aggressive in their consumption of the dwindling
CO2.
One thing that has been shown across the world as the industrialized nations
have increased the burning of coal is that CO2 levels in the air increase,
and this predictably has led to an increase in crop yields. In fact when
they compare droughts (remember, plants need more water when there is less
CO2 in the air) from the 1950's when CO2 levels were quite low to todays
comparable droughts they have found less crops die and there is less
famine - the plants which could not survive and died from lack of water in
the 1950's actually do better today by not needing as much water since
there's more CO2 available for them.

So in contrast to what we've been told over the last few decades, the way to
'save the world' may counterintuitively involve using up all that locked
away carbon by burning it for our own power needs, replenishing the air and
allowing the plants to proliferate again. It would mean they'd use less
water, allowing more ground water to accumulate, it would allow smaller
farms to
produce far more food meaning humans would not need to use as much land for
their own purposes.

just a thought

-karl



PS: Antonyms are words that are opposites such as:
skeptical <-----> gullible
pollutant <-----> nutrient