Argument: CO2 levels have not caused global warming in the historical record
- Studies of ice cores show that carbon dioxide levels rise and fall with or after (as much as 1000 years) temperature variations. In other words, carbon dioxide levels could not be a cause of temperature and climate change. This argument assumes that current climate change can be expected to be similar to past climate change.
- "The Great Global Warming Swindle. CO2 & Temperature (also see Temperature Record)." WagTV. Retrieved 12.12.07 - "The ice-core data is frequently cited as principal evidence to argue that CO2 is the earth’s main climate driver. It is, in a way, the jewel in the crown of the theory of man made global warming. But the ice-core data does not show that CO2 drives climate. It shows, very clearly, that variations in temperature precede rises in atmospheric CO2 – not the other way round. The two phenomena are divided by a time lag of several hundred years."
- While the historical record does demonstrate this to be true, C02 is a greenhouse gas, and the recent timing of its mass emission into the atmosphere is NOW the cause of the more recent, and dramatic global warming. This argument asserts that the modern era of human carbon emissions is different than all historical trends, invalidating the use of these historical trends as an explanation of what is occurring today. It also asserts that recent global warming is occurring before or faster than it would have occurred due to natural forces; the cause being human greenhouse gas emissions.