Hi All. I have been thinking recently that I have been too close minded with respect to the supposed evidence Anti-AGW posters have been bringing forth. Rather than having an "I'm right, you're wrong" debate, could we discuss the fundamentals of why you reject human-activity as a significant cause of global warming? Make sure to cite your claims with peer-reviewed, academic sources. You may link to blogs or other articles so long as they are not overly partisan and back up their claims with academic sources.
I am also interested in knowing why you think the scientists who study this are wrong. Perhaps you could focus on this as well.
"Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities"
Source:
Climate Change: Consensus
No, it's not 97% of climate scientists. When a
proper survey is done it's more like 78% of climate scientists who publish peer reviewed work about the climate, 61% of meteorologists who publish mainly about climate, and 52% of all scientists. This is on the question of whether GW is AGW.
As I have been showing for a while, there is plenty of peer reviewed literature that backs up a skeptical position about AGW. The most recent IPCC report downwardly revised estimates of climate sensitivity, for example, vindicating many of the skeptical scientists who said that the estimates published previously were too high.
The whole issue of whether GW is AGW and will turn into CAGW (catestrophic AGW), hinges on climate sensitivity.
The effect of doubling of CO2 atmospheric concentrations per se is calculated to increase global temperatures by 1.1 degree C. This figure is completely non-controversial. We get CAGW, with elevations of 3 to 6 degrees, by adding in positive feedbacks, mostly feedback from water vapor. So then the question is whether or not there is a strongly positive feedback from water vapor.
It has been very difficult to settle this question. The problem is that water vapor can change states, into water or ice. When that happens the effect on warming can completely change, from positive to negative feedback. The models used to predict global temperatures have already been shown to be predicting temperatures that are too high. These models can't model water vapor, snow, ice, clouds and rain and the process that converts one to the other. The modelers rely on guesses about that. The guess has always been that the overall effect of the water cycle is a strongly positive feedback. This is probably wrong. It's not born out by the
data from satellites, which
don't show such a feedback.
The reason why modelers continue to insist that water vapor provides a strongly positive feedback is simple. Without that there can be no CAGW, no scary scenarios, no funding for their work.
Also, historically climate sensitivity hasn't been at anything like levels claimed for the models. If we assume Hansen is correct and significant AGW started in 1950 then the transient sensitivity up to this point has been 1.58 degrees C for an increase of atmospheric CO2 of 270 ppm (doubling).
If data from the tropics is taken as a whole it's clear that clouds and rain have a big effect on warming in that they provide a negative feedback. The more ocean waters are warmed the more water vapor is dissolved in the atmosphere the more clouds form. These tend to cancel each other out, and the overall effect is a small feedback, slightly positive or negative.
So, climate sensitivity isn't likely to be as high as climate scientists have claimed. Probably more on the order of 1.5 degrees C, which means that GW or AGW it isn't a big deal.
The other aspect of the issue is this: Let us assume that AGW is real and will cause significant warming in time. What do we do about it? The most recent climate summit they are saying that all nations should cut their carbon emissions by 50%. This is such a ludicrous recommendation that the IPCC is distancing itself from it. It is clearly impossible to meet this recommendation and that pretty much puts an end to climate science as a driver of public policy, imo. Japan has already officially checked out. Climate policy advocacy was already seriously wounded from Copenhagen. Not to mention all the little island nations who came to the summit looking for money, NGOs looking for money, etc.. One gets the picture about what is really going on.
So, what can be done? Policy wonks point out that just waiting until the warming actually shows up, if ever, and then adjusting to it would cost one fiftieth as much as trying to mitigate it. That is probably the better approach.
The mystery to me is why we are even talking about this when there has been no significant global warming since before my teenage nephew was born. During that whole time atmospheric CO2 was going up exponentially. Historically, correlation between CO2 and temperatures has been pretty poor in the near term, which suggests that the whole idea that CO2 drives the temperatures is wrong, but that's for the advanced class.
eace
