The important science issue here is weather or not the increase in CO_2 is caused by warmer temperatures or drives warmer temperatures>

The ice core data does not have enough time resolution to easily address this.

Below is an image of the carbon cycle. How might ice ages effect some of these exchange processes and rates?

• Reduced source from bacterial decomposition of dead matter in soils

• Increased sink as greater snowfall (which causes the movement of continental ice sheets) precipiates out more CO_2.

• Also there is likely decreased production in the oceans from decomposition due to lower mixing rates between surface layers and deep layers

What this higher time resolution comparison seems to show is that atmospheric temperature seems to rise before CO₂ starts to rise.

There is a sound physical reason for this.

The oceans are buffers and sources of stored heat. As the earth naturally warms from emerging out of an ice age, this stored ocean energy also begins to heat the atmosphere and then its ability to store CO₂ increases.

This is particularly evident if you look at the period from 12,500 to 11,000 years ago.

So the ice core data seems to be telling us that CO₂ buildup follows atmospheric warming and does not cuase it.

But, that doesn't mean anything today! Look at the slope of the red line today (far right of the graph). The rate of build up is unprecendent and could certainly reverse the situation where CO₂ does produce warming.

This is the most important science message.

Rates matter. Qualitative conceptions don't.