Carbon dioxide is by far the most significant of the greenhouse gases, despite its low concentration, Carbon dioxide occurs in the atmosphere at only 385 ppm (parts per million), which translates into a slim 0.0385% of the total volume of atmospheric gas. Before the beginning of the industrial age, the level of carbon in our atmosphere was only 280 ppm.
The Carbon Cycle
Carbon is also a basic building block of living organisms. Trees, grasses, and other plants absorb carbon as they grow. When these plants decay, or are burned, the carbon is released back into the atmosphere. Deforestation and the conversion of wild lands for human use are also adding enormous volumes of carbon to the atmosphere.
Heat waves and ice ages have resulted, on a global scale, over the many millennia of Earth’s existence as a consequence of carbon cycles. Carbon has cycled from land, to ocean, to air. The ocean itself is a vast repository of carbon, containing 50 times as much carbon as the atmosphere.
Current CO2 Emissions
The current situation is different in that we are forcing a change in the chemistry of our atmosphere that has no natural or historical precedent.
The latest research is concerning, in that the current levels of carbon in the Earth’s atmosphere correspond with periods in our past when the Earth was much warmer, and sea levels were hundreds of feet higher than they are now. That is something we should all be worried about.
CO2 Production During Combustion
One of the most significant causes of global warming is the CO2 released from the burning of fossil fuels. All fossil fuels contain carbon, which, when combusted, bonds with oxygen and forms carbon dioxide that enters the atmosphere. Coal, burned primarily to generate electricity, puts more carbon into the atmosphere than any of the other fossil fuels.
Carbon dioxide cannot be mitigated through pollution control technologies in the same way as other pollutants. Carbon is an elemental product of combustion, and cannot easily be removed from the gaseous output of any fossil fuel machinery.
It may be prohibitively expensive to apply carbon sequestration to electrical power stations. Currently, research is being conducted on sequestering carbon from coal-fired power plants. Although that may help– if it works– it will not be applicable to other fossil fuel machines, such as cars and trucks.
Author: Brown, Nathan. A Cooler Climate, 2008.