[thackney]

How many warming/cooling cycles have been documented?

[aruanan]

Note, though, that in this graphic, most of the eruptions appear to be either after it started getting colder or as things were getting warmer. Note especially the Little Ice Age. On the warm-up side there were a LOT of eruptions, but not immediately, within "weeks or months" of a cool-down except, perhaps, after Mt. Pinatubo.

[M. Dodge Thomas]

There is no reason why AGW cannot be occurring in addition to other natural climate drivers (actually, it likely interacts with them).

You can even - if you wish to - consider human climate drivers just another "natural phenomena" - we are part of nature, after all.

We just happen to be a natural phenomena which is raising CO2 concentrations pretty quickly on the time frame in which we have been operating.

And there is nothing about this observation which implies that on a longer time frame there might be other natural phenomena which would act as more significant drivers of climate, or that over shorter time frames there may not be other natural phenomena (such as volcanic activity) that might be even more influential.

So what often strikes me as odd about this debate is the conviction that human activities are somehow so "different" that we are reluctant to apply quite well understood aspects of physics and chemistry to evaluating their likely results.