As an engineer who has worked in the environmental field for over 30 years, I am pleased to see that you acknowledge the improvements that have occured to our nation's air and water quality in the last few decades. Much of these improvements can be attributed to actions by our federal government (i.e. Clean Water Act, Clean Air Act, RCRA, CERCLA, etc) which were intended to mitigate the adverse effects of industrialization, population growth and economic development, etc. Many of these laws have set specific emission standards and discharge regulations for a host of human activties. Engineers and scientists have devoted an enormous amount of time and resources researching pollutant fate and transport to determine the reductions in pollutant emissions that was necessary for a given improvement in the environment. Much of this work involved mathematical modeling of the physical,chemical and biological environment similar to what is occuring now in the climate change arena and indeed by some of the same people. While it is unfortunate that politics has entered the climate change debate, from my perspective in the scientific community,there seems to be a clear consensus that human activity is having an effect on our climate. There is, however, disagreement on the amount of change and what that may mean to something like the mean sea level 50 years from now. I guess my point is that we have been there before. We recognized the problems with our nations air and water quality 40 years ago and did something about it. We used many of the same tools that are being used by today's researchers in the climate field. Obviously it is very complicated and there is plenty of room for debate over the science. Over the years, I have seen new issues arise every few years in the environmental business. As we solve one we begin to look at another. Why is it so hard to believe that only politics is behind the greenhouse gas issue? To me it is just another environmental problem that we need to address and the people involved in this effort are no less dedicated that the ones who have been working to improve our nation's environment over the last 40 years.

Actually, as an engineer a "consensus" is important to me. While it is always possible that the "consensus" has gotten it wrong, the more researchers who can replicate and confirm each other's work from a variety of approaches the greater the probabilty that their hypothesis is correct. My main point, however, is that most (if not all )of the researchers who support anthropogenic climate change are hard-working honest people who are using the best tools available to them to answer a difficult question. I don't think their research is politically driven. That's all.

Sorry, saw you third response after I posted my second one. I was wondering about your anti-economic development argument. Some believe that our environmental regulations are such while others believe it just fairly apportions external costs. If you support the environmental laws (and their associated costs)that led to the improvement in our nations environment,why would it be any different for CO2. We presently spend large sums of money reducing S02, VOCs, Pb, CO, NOx and Particulates in our air, and a host of other pollutants in our water. Presently, the environmental community may be struggling to figure out how to control CO2, to what level, at what cost and how to deal with issues like China and India but on principal we are talking about regulating another pollutant. We regulated an enourmous number of activities over the last 40 years or so, and it hasn't stopped economic development.