[jwalsh07]

What would be convincing is predictions of global temperatures for some limited time in the future, say five or ten years. These could be compared to predictions of other models If GW models outperform the others significantly in that time frame, it might be reason enough to act.

Hansen made predcitions for global temperature increase 10 years ago. He was off by only about 800%.

Global warming has been happening for many, mnay years now, thank goodness since the alternative is not a pretty picture.

The problem with scientists like Hansen is that they suffer no consequences from predictions that were so inaccurate a 2 year old chimp could have made them.

So the Earth is warming. For those who think that is a catastrophic problem they have two choices, they can offer methods to mitigate global warming, color me very skeptical here, or they can do some science taht allows Earths inhabitants to adapt. They choose to do neither and thus get the well deserved reputation as the boy crying global warming, or cooling, whatever the cureent fad is.

As for CO2, I would love for somebody to give me proof that CO2 leads temperature increases rather than lags. The charts I've seen from ice cores seem to indicate that CO2 upticks lag temperature increases.

[Torie]

As for CO2, I would love for somebody to give me proof that CO2 leads temperature increases rather than lags. The charts I've seen from ice cores seem to indicate that CO2 upticks lag temperature increases.

Oh dear! What does it mean? You must be in law school now or something. Does it mean, that CO2 just accelerates what was imbedded in the sun activity or something?

[cogitator]

As for CO2, I would love for somebody to give me proof that CO2 leads temperature increases rather than lags. The charts I've seen from ice cores seem to indicate that CO2 upticks lag temperature increases.

Which is correct. Glacial-interglacial transitions are correlated with Milankovitch cycle (solar insolation) triggering/forcing*. I.e., when solar insolation is at a minima or maxima due to superposition of the Milankovitch cycle maximas (or minimas), this marks the transition point. Following maximas, there will then be a rapid decrease in solar insolation, triggering entry into a glacial period. Following minimas, there will then be a rapid increase in solar insolation, triggering entry into an interglacial period. Once either entry is underway, there are two main feedbacks: CO2 increase or decrease due to warming or cooling oceans, respectively, and retreat or advance of continental ice sheets. Both are positive feedbacks augmenting the transition direction. For a warming phase, increasing atmospheric CO2 creates more warming, releasing more CO2 from warming oceans, etc.

There is insufficient energy available for the solar insolation variability to induce the full range of temperature change observed. Atmospheric CO2 is the only known, quantified factor with sufficient energy to cause the full range of temperatures. There have been some theories about other solar cycle causes, but they will require much more evidence to effectively supplant the current understanding of glacial/interglacial variability.

* Not all the details of the glacial/interglacial record correlate with Milankovitch cycle solar insolation variability. Most of the variability does correlate well with Milankovitch.