Its hot... We're all gonna die!!!

Believe it or not, some people wanted me to write a post again.

This whole issue of global warming has really been frustrating me a lot lately. Mostly because I don't really know anything about atmospheric science and the claims by some that human-caused CO2 emmissions will eventually destroy life as we know it today just seem to be far fetched to me.

Anyways, since I have been researching it lately, the biggest confusion and disagreements in the scientific community seem to be on the effects and outcomes of the modest warming observed and not on the warming itself. This may be surprising, because I think that most people, as I once did, think that the debate is over wether or not earth is experiencing observed warming. This is not the case. I had a professor who made a statement in a graduate electrical engineering course that earth's polar ice caps are melting, and yet some people in politics (his tone was jocular) think that global warming is not happening. As far as I am concearned, he displayed his ignorance of the subject, because that's not the issue.

The global mean temperature has increased by One degree Farenheight over the last century, which, this change is comparable to the interannual variability in global mean temperature (so says Richard S. Lindzen from MIT). There is certainly some debate over the cause of the global mean warming, but most scientists seem to agree that increasing CO2 levels as observed over the last century would amount to some of the warming observed, not necessarily all. There are even some scientists that suggest that the warming we currently observe has mostly to do with heightened sun activity. The heightened sun activity explanation also helps explain, in my opinion, why Mars is also experiencing and apperent "global warming" along with planet earth. I haven't heard anybody else say this theory or reject it, but it seems logical to me, since both mars' and earth's atmospheres are under the influence of the sun.

It is very difficult for any lay person to form an educated opinion on the effects of Global warming without lauching years of investigation. So we are pretty much left to honest summaries given by the professionals in the field. A very good summary and professional opinion on the current state of the scientific data (as of May 2001) was given by an MIT professor, Richard S. Lindzen, in his testimony before the US Senate on Global Warming. If you want an interesting and informative read, I would read the testimony I just linked to, but I will just quickly summarize the most interesting points to me.

Lindzen says that what scientists agree upon, in summary, is:
1) that global mean temperature has probably increased over the past century
2) that C02 in the atmosphere has increased over the same period
3) that the added C02 is more likely to cause global mean temperature to increase rather than decrease
4) that man, like the butterfly, has some impact on climate.

At this point, if you are still interested, you should probably read the aforementioned testimony and stop reading me. However, just to make my summary a little more complete, I'll include some particularly strong and interesting points from his testimony.

As for my summary, I think Lindzen basically is saying that...
1) The earth has warmed One degree Farenheight over the last 100 years and most scientists do not despute this.
2) CO2 levels have increased over the same time interval (280ppm to 360ppm).
3) Doubling CO2 in the earth's atmosphere would, by straight forward calculations, account for about a Two degree farenheight change in Global mean temperature, and that any heigher estimates are due to positive feedback effects in the atmosphere. The positive feedback effects are not at all verified, and in fact, a lot of research suggests a very strong negative feedback effect which would cancel out much of the warming.
4) The Kyoto Protocol wouldn't do anything which would be noticeable.
5) Computer models that predict weather catastrophies from the exaggerated rise in global mean temperature (exagerated from the strong positive feedback assumptions) pretty much suck, because they couldn't even predict what we know has already happened in retrospect (El nino as one example).
6) The observed changes in temperature are within the known natural variability of global mean temperature, and therefore it is very hard to link the variability that we are currently observing ( 1F over last 100 years), to human activity. In order to do so, you have to claim to know exactly why the temperature naturally varies apart from human activity, otherwise you cannot pin the observed change on industrial CO2 emmissions. (I would like to know exactly what the natural variability has been over the last 100 years, and how we know that. Lindzen doesn't say in this testimony.)

I found Lindzen's testimony very insightful, and he certainly has the credentials to make his opinions serious.