wbjones, evidence of past glaciers in the American Southeast does not support the economics of the exchange of carbon credits. Therefore, it is not valid.
Tommy, the greenhouse effect most definitely works. We have known about this for a long time. See Venus. The main components of the Venusian atmosphere are carbon dioxide (96%), nitrogen and sulfuric acid. http://www.nasa.gov/worldbook/venus_worldbook.html At this time, there has been no measured amount of free oxygen. The question is, how did it get that way? There are no Venusians roaming the planet driving SUVs or burning coal. That indicates it was a natural process.
Then we can go the other way entirely with Mars. The Martian atmosphere is 93% CO2. http://www.nasa.gov/worldbook/mars_worldbook.html Yet it is much colder and drier than Earth.
One would think that two planets having similar CO2 densities orbiting the same star would, regardless of distance, show some temperature correlation. But that is not the case.
Then we take Earth. CO2 makes up less than 1% of the atmosphere. http://www.nasa.gov/worldbook/earth_worldbook.html 78% is nitrogen, 21% is free oxygen. But Earth falls in a much more comfortable category (for us, anyway) than Venus or Mars despite a much lower CO2 percentage.
That tells me there is much more to climate change, or global warming, or whatever the term du jour is than merely CO2. I personally think it's much more tied to water vapor. But no one is marching with signs screaming 'STOP EVAPORATION NOW!'
I don't think we should keep dumping crap into our environment. This is the only planet we have (at the moment) and it makes no sense to foul our nest. We have made large strides in cleaning things up since the 1960's, when all kinds of stuff was dumped everywhere with no thought as to its effect on future generations.
But I don't think cooking numbers to support a single ZOMG!!!WE ARE ALL GOING TO SLOWLY ROAST!!!! theory is the way to get the populace to go along with needed changes. It needs to be something seen in the back yard (see: NIMBY).
Down here, people near a coal fired electric plant started flipping out when they found black specks in well water, they immediately blamed the coal plant. Turned out it was minute specks of various plant material but there was no coal dust. Still, it raised awareness of the possibility of ground water contamination by coal dust and has made people seriously consider cleaner alternatives such as hydroelectric and nuclear plants. Me, I vote nuc; much simpler to build and sustain.