Your Attention Please! There are now 4 kinds of lies!

<div class='quotetop'>QUOTE(vtie @ Sep 16 2007, 01:35 PM) [snapback]513360[/snapback]</div>

I'm surprised that nobody has mentioned the obvious - global warming did not exist until the advent (or discovery) of dark matter. We know that friction causes heat, so –

The earth spinning on its axis, traveling through space, is rubbing against lots of (or for the science minded - substantial amounts of) dark matter - thereby generating heat.

Proof? Proof is for the mathematician, I'm just an idea person. Science? I leave the science to the scientist.

 

Of course! It's the aether! Why didn't I think of that? Michelson and Morley will be delighted.

 

<div class='quotetop'>QUOTE(vtie @ Sep 16 2007, 01:35 PM) [snapback]513360[/snapback]</div>

Even though there might be just one (gynourmous) model to study an accurate model should be able to make testable predictions. Indeed, this is the case with climate models. This is a good reference that discusses modeling and is skepticism:

http://gristmill.grist.org/story/2006/11/19/51921/827

Note the many primary references within the article.

Hindcasting is noteworthy. Roll the clock back in the model to the past when all conditions are known and documented. Models hold up well in that regard as well.

 

<div class='quotetop'>QUOTE(Alric @ Sep 17 2007, 04:41 AM) [snapback]513489[/snapback]</div>

I never claimed that you can't build a scientifically valid model for our climate, I only said that there are some complications because we only have one object to study.

For example, suppose I do a simple correlation analysis between the average temperature and the CO2 concentration over the last 20 years. I then extrapolate that trend in order to predict a further increase over the next 10 years. And it works! I have made a testable prediction that works. Does this mean that I have scientific evidence that this global warming is caused by the increase in CO2? Not at all. Correlations never prove causality, that is one of the first lessons of data analysis. Hindcasting are even more dangerous, because all models are fitted to present and past data. So, you synthetically reduce the degrees of freedom in your model.

Does this mean that we should not do anything about the increase of CO2? The answer is again negative. Because of the nature of the threat, even a possibility is enough to justify action. Preserving our Earth is not a scientific discipline at all. If we wait until it is scientifically proven beyond reasonable doubt, it might just be too late.

 

<div class='quotetop'>QUOTE(Wildkow @ Sep 16 2007, 06:13 AM) [snapback]513260[/snapback]</div>

Umm, what else do GW advocates push for besides energy conservation and cleaner sources? It sounds like you are for both of those, so why waste your time disagreeing on the reason? How is addressing GW wasting time, even if it turns out we're wrong?

And on the earlier point, %0.28 per year added by humans. That's about %1 every four years. In a century we will have added a quarter more to the CO2 in the atmosphere. As someone stated before, the ecological system can't re-sequester this increase. Regardless of how much it would affect temperature, it can't be good to keep adding more and more carbon to the atmosphere.