Hello Friends,
I took an Environmental Biology class this summer and the carbon cycle is taught in basic nonpartisan science class. This is a very serious problem. Carbon levels balance the Earth's temperature. It is true that the cycle would fluctuate on it's own regardless of human contribution. But the effect of pumping carbon dioxide into the environment in massive amounts is throwing off the cycle by leaps and bounds. The warming is going on at an alarming rate. Unlike any natural trend. People don't really know what's going to happen because this massive Earth experiment has never occurred before. But when the carbon cycle is taught in basic science class there is no question as to the process. The people trying to sell something are the ones making their money on carbon emissions. Here's a link to the Intergovernmental panel on Climate change report.
http://www.grida.no/climate/ipcc_tar/wg1/index.htm 
The problem is that in extreme conditions there can be a "tipping point" where the cycle goes out of the natural process then the effect continues to trend upon itself. Just like the human body has a natural process of realigning itself, we still have to do the things that stop ill health from causing trends of ill health. I have high blood pressure and it is a natural process, but the last thing that I would do would be to drink buckets of salt water everyday.
The natural process of realignment is true in global warming but if the process is sped up so fast the natural process won't be able to catch up. The ice on our planet reflects the sun's raze and keeps the temperature in check. The greenhouse gas effect also trap's the sun's heat in the atmosphere. Deforestation is also detracting from the Earth's natural defense systems of regulating temperatures.
http://www.youtube.com/watch?v=w_L72_SDO28&feature=related 
