News flash! Carbon Dioxide is the thermostat control knob for the Earth's climate. So sayeth NASA's GISS scientists Andrew Lacis and Gavin Schmidt. How do they know? Why computer models of course of the most cunning simplicity.
The nub of all who believe CO2 causes global warming can be found in this one sentence in the NASA press release: The study ties in to the geologic record in which carbon dioxide levels have oscillated between approximately 180 parts per million during ice ages, and about 280 parts per million during warmer interglacial periods.
Except there is one problem with this. From established geological data in this graph, our current era has the second lowest concentration of CO2 in the atmosphere. For a comparison, lets look at the Ordovician era where CO2 concentrations was approximately 4,500 ppm yet the Earth's temperature plummeted. Of course one reason why the temperature plummeted was when Gondwana passed over the Arctic, that would seriously chill things out. Extenuating factors can play merry hades with a theory, just like the current shortfall in solar output is doing to the current global temperature.
Or from more recent times from the Vostok ice cores in Antarctica comes this bit of information. It seems variations in temperature for deglaciation are either in phase or lag by approximately 1000 years any change in CO2 concentrations. So current hard data can be considered equivocal to supporting CO2 as being the control knob for temperature change.
So reality or actual data seems to refute the Lacis and Schmidt computer model. And until the computer models can track with actual data, place this report with the guys from Mythbusters.