The Global Warming Gas, or The Bread and Butter of Life?
By
Viv Forbes, Chairman,
We are told, incessantly, that carbon dioxide is the main cause of
global warming – it is not.
The primary source of surface
heat is radiant energy from the sun. Minor heat comes from geothermal energy
from volcanoes and hot rocks. Trivial quantities of local heat are brought to
Earth’s surface by humans using stoves, cars, boilers, engines and factories
powered by mined fuels such as coal, oil, gas and uranium. Even using “green”
energy such as ethanol, wind or wood has a tiny temperature effect by
transferring solar energy from farms and forests, to be released eventually as
waste heat in cities.
Solar energy is more concentrated
in equatorial areas and is moved pole-wards by the circulation of air (99.9%
nitrogen, oxygen and argon), and by water and water vapour via evaporation,
condensation and ocean currents. These processes are all driven by conduction,
convection, latent heat and Earth’s rotation, not carbon dioxide. They are the
major forces creating weather. Variations in solar cycles and cloud cover
control longer term climate change.
Carbon dioxide plays almost
no part in any of these dominant weather processes. Moreover, it does not burn,
nor is it radioactive – it cannot produce heat.
The so called greenhouse
gases (mainly water vapour and carbon dioxide) have the ability to absorb
radiant energy and transmit it to their surroundings. These gases tend to
retain some surface heat but also assist the Earth to shed heat from the upper
troposphere by radiating energy to space. Without this ability to shed heat to
space, the upper atmosphere would be considerably hotter.
However, carbon dioxide
occurs in tiny trace amounts in the atmosphere, and any surface heating it
could do is already being done by water vapour, which is more abundant and
affects far more energy wavelengths. Also, the greenhouse effect of carbon
dioxide is almost exhausted after the first hundred parts per million – adding
more has very little effect on Earth’s surface temperature.
The net atmospheric effect
of additional carbon dioxide is thus very minor and difficult to
quantify. It probably makes the nights slightly warmer, especially in
higher latitudes during winter; and it probably has little effect on daytime
temperatures.
But additional carbon
dioxide in the biosphere gives a major boost to all plants which feed all
animals. It is not a pollutant, anywhere.
Carbon dioxide is not the
gas of global warming – it is the bread and butter of life.
More reading for those
interested:
Carbon dioxide greens the
deserts:
G'day Jim
ReplyDeleteBeen away for a couple of weeks - now I'm back.
Just read your last six posts, are you the same bloke or, do I detect a new slant in your musings?
Not a complaint you understand, more a pat on the back for the content and your comments.
I wasn't aware of much of a change PD, but now you mention it may be evolving a bit. This one is of course by Viv and I can't claim any credit for it.
ReplyDelete