These so-called debates over global warming and climate change usually turn my stomach because of the sheer ignorance displayed.
Thanks go to KEW, Irvrobinson, and to a lesser extent highfigh, for recognizing that carbon in its various forms (different levels of oxidation) are part of cycle in nature, the carbon cycle. Apparently they do remember basic high school biology. (highfigh, you'd get full recognition if you didn't make the wrong conclusions from basic facts
.)
In the carbon cycle, animals and microorganisms use oxygen from the air to chemically obtain energy from food carbohydrates. This process, called respiration, carbon dioxide (CO2) is produced. In this cycle, green plants and algae also use sunlight to convert CO2 into carbohydrates, producing oxygen in the process. This part is not minor – there is an equilibrium between the rates respiration and rates of photosynthesis.
As the carbon cycle goes round, the
rates of CO2 formation and the
rates of CO2 consumption become critical. In addition to animal and plant respiration, CO2 is also produced by non-biological oxidation – fire. Burning wood, coal, oil, and gasoline, produces large amounts of CO2, altering the ebb & flow of the carbon cycle. In addition, clearing northern and tropical forests has significantly reduced the amount of photosynthesis. Some of this cleared forest is replaced by agriculture, but the amount of agriculture-produced photosynthesis is quite a bit less than the forest it replaced.
As a result of all this,
changing the rates of CO2 formation or CO2 consumption has a big effect. Much bigger than if you only look at the
total amounts of CO2 in the atmosphere. Nearly all of this change has occurred over the last 150 years.
There are several important physical, chemical, and physiological properties of CO2 that should be remembered:
- CO2 is a minor component of air, a trace gas, presently amounting to 0.04% (410 parts per million, ppm), having risen from pre-industrial levels of 280 ppm.
- CO2 is an asphyxiant gas and is not classified as toxic or harmful. In concentrations up to 1% (10,000 ppm), it will make some people feel drowsy and give the lungs a stuffy feeling. Concentrations of 7% to 10% (70,000 to 100,000 ppm) may cause suffocation, even in the presence of sufficient oxygen, with dizziness, headache, visual and hearing dysfunction, and unconsciousness appearing within a few minutes to an hour.
- Not all CO2 produced by respiration gets released directly to the air. Much of it can be stored dissolved in water, in the seas, underground, and in ice.
- The amount of CO2 that dissolves in water or ice is temperature dependent. Cold water can contain much more CO2 than warm water. As the planet warms, much of the CO2 dissolved in the ocean is released to the atmosphere. Polar ice cap and permafrost soil can trap large amounts CO2, keeping it out of the cycle – until global warming releases it by melting the ice or permafrost.
- CO2, when dissolved in water, undergoes a chemical reaction with water, producing bicarbonate, a weak acid, and ultimately carbonate, a stronger acid. As the atmospheric content of CO2 increases, the oceans and fresh water of the world are gradually becoming more acid.
- CO2 is a greenhouse gas. In the atmosphere, it reflects heat. It keeps the Earth warmer, much as blanket keeps us warmer on a cold night. As the amount of CO2 in the atmosphere increases, the warmer oceans and fresh water release greater amounts of stored CO2, and the permafrost and polar ice caps melt, releasing even more CO2.
- CO2 is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution man-made emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.
It is overwhelmingly clear that this change over the last century & a half has indeed happened and that it's significant. To argue that it is natural vs. man-made is ignorant – or worse, its a self-serving effort by the carbon-based energy corporations to delay any efforts at forstalling global warming. We don't know for certain that any efforts to slow global warming can help, but we do know that doing nothing will continue to make things worse. [\Rant/School Lecture OVER]
