I do feel bad ;) - yes, I am aware that the thermodynamics of our atmosphere are extremely complex, so complex that we can barely model them. This is exactly why I advocate people to be wary of when any scientist claims "x is going to happen in y years" -- we simply do not know how our atmosphere will behave, no more than we know what the exact weather will be like in two months. Right now, everything is basically a theory - we know that CO2 warms the atmosphere, but we do not know how much CO2 will be in the atmosphere in 2 years (we do not even presently have an exact amount).
We don't need to know exactly how much CO2 will warm the atmosphere. We have a probability distribution. We can't quantify the economic damage of climate change precisely, but we know enough to know it won't be $0, which is what the "wait and see" point of view prices the cost as.
Also, climate change isn't even the big issue here. I'm talking about much more mundane and also much more damaging air and water pollution from factories, cars, etc. We have very solid empirical evidence about that. Did you know that after the EPA's ban on leaded gasoline, blood lead levels in children dropped by a factor of 3-5x in just one decade? See: http://www.epa.gov/ace/body_burdens/b1-graph.html. This corresponds to a multiple IQ-point impact from lead. What's the dollar value of a multiple IQ-point impact on the nation's children (and future workforce)? It's a huge number.
Did you know that a recent Harvard Medical School study concluded that the true price of coal power factoring in the externalized environmental costs is 2-3x as much as the market price? http://www.boston.com/lifestyle/green/greenblog/2011/02/new_.... The same study found the total externalized costs of coal power to be $200-$500 billion/year: http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.2010..... Here in Chicago we recently shut down two coal-fired power plants that were causing $100 million in health damage per year and only creating 50-60 jobs each.
The total cost of environmental damage being down every year, in terms of quantifiable impact to people is probably into the trillion dollar per year range. People tend to think of environmentalism as being about "soft values" but that couldn't be further from the truth. Even if we assign zero value to the environment itself, we can't avoid putting a dollar figure on the value of the services the environment provides us. When New York manages to avoid building a $6-$8 billion filtration facility by properly managing the Catskills watershed, we can't avoid the inescapable economic conclusion that damage to the Catskills and similar watersheds needs to be valued in the billions of dollars range. We can't avoid the conclusion that when a company dumps waste into those watersheds, it's an economic injury no different than if tore up city streets or caused a bridge to collapse.
It's the government's job to protect us from all this, the same as it's the government's job to protect us from people who steal your car or break into our houses. It goes to the heart of why government exists.
