Definition of Carbon Dioxide CO2

Photosynthesis

An excerpt from an article by Ray Evans “Nine Facts about Climate Change”

Carbon dioxide is necessary for all life on earth and increasing atmospheric concentrations are beneficial to plant growth, particularly in arid conditions.

Because the radiation properties of carbon dioxide in the atmosphere are already saturated, increasing atmospheric concentrations beyond current levels will have no discernible effect on global temperatures.

Carbon dioxide (CO2) is a colourless, odourless, tasteless, non-toxic gas which is essential to all life on earth. (Carbon monoxide, however, is extremely toxic and will cause death very quickly if inhaled.) All green vegetation requires carbon dioxide as plant food and the process of photosynthesis, in which plants take in carbon dioxide, absorb solar radiation, store the carbon and emit oxygen, is basic to life. As concentrations of carbon dioxide increase, the rate of growth of plants also increase. Flowers and vegetables grown in hothouses are frequently fed with extra carbon dioxide for faster growth and higher yields. As atmospheric concentrations of carbon dioxide have increased from approximately 325 ppmv (parts per million by volume) in 1970 to 375 ppmv today, wheat yields in Australia have increased in the last 30 years, in part because of CO2 enrichment.

CO2-Water Cluster

Every time a story on global warming is featured on TV, either a background image of the cooling tower of a power station, with its plume of minute water droplets above, or of an old power station (perhaps long since retired) with a smoke stack belching forth dark plumes of soot, fly ash and other particulates, is shown. In this mendacious way, carbon dioxide is identified as a serious pollutant, and the US is always labelled as the world’s greatest polluter. (Australia was singled out by Sir Nicholas Stern, formerly of the World Bank and now adviser to the UK Government, for particular condemnation in his report of 30 October 2006.)

Coal-fired power stations which have modern flue-gas scrubbing equipment built into their exhaust systems will have smoke-stack emissions which are barely visible. Carbon dioxide cycles naturally through the atmosphere, the earth’s land mass, and the oceans. Huge volumes of carbon dioxide are injected into the oceans and atmosphere during earthquakes and volcanoes. The amount of carbon contained in atmospheric carbon dioxide is about 730,000 million tonnes (730 Gigatonnes of carbon (GtC)). The annual transport of carbon to and from the land surface and the atmosphere, is estimated at 120 GtC; between the oceans and the atmosphere the estimate is 90 GtC.[10] The annual emissions of carbon dioxide to the atmosphere resulting from human activities is, by comparison, about 7 GtC, or less than 1 per cent of the total atmospheric carbon mass, and less than 4 per cent of the natural annual emissions from the biosphere and the oceans. Changes in the natural transport of carbon, as well as human activities, have led to recent increases in atmospheric concentrations of carbon dioxide.

Sun Energy and Photosynthesis