A complication in the simplest argument about carbon dioxide and temperature is that the CO₂ appears to increase slightly later than the temperature increase. A thorough discussion of this issue is here, from http://www.searchanddiscovery.net/documents/2009/110116flower/ndx_flower.pdf. It is generally agreed that a perturbation in temperature (possible causes given in the chapter on climate) triggers an initial release of carbon dioxide, for example from gas dissolved in the oceans. This gas amplifies the temperature increase through greenhouse warming. Such models can yield the small phase lag in a natural way. They show that the carbon dioxide greenhouse substantially amplifies the temperature swings and is responsible for the bulk of the warming, although the incidents get triggered in other ways.