One of my frustrations in arguing that anthropogenic global warming forecasts are exaggerated is that people usually respond, "well, we should do something anyway just in case."  As if the cost of abatement were nearly free.  But the one thing we know is that any meaningul abatement of CO2 production will be extraordinarily costly to the world economy, and will have real and predicatable impacts on poverty and development. 

We are perhaps fooled by past efforts at reducing pollution, where we have greatly improved air and water quality when we wanted to.  The elimination of SO2 pollution is one example.  But the difference is that these ancillary pollutants were not fundamental to the combustion process.  Hydrocarbons + O2 ==> CO2 + H2O.   Key pollutants we have fought in the past — ozone, SO2, NO2 — are not core to the combustion process.  They can be managed through cleaner fuels, some filtering, and better control of the combustion process itself.  CO2 is different.  There is no practical way to filter it cheaply.  The only real way to eliminate it is not to burn hyrdrocarbons.

As a result, small improvements in CO2 levels require enormous investments:

Last July, this column reported that the latest global warming bill — the Low Carbon Economy Act of 2007, introduced by Sens. Jeff Bingaman, D-N.M. and Arlen Specter, R-Pa. — would cost taxpayers more than $1 trillion in its first 10 years and untold trillions of dollars in subsequent decades.

This week, the EPA sent its analysis of the bill’s impact on climate to Bingaman and Specter. Now we can see what we’d get for our money, and we may as well just build a giant bonfire with the cash and enjoy toasting marshmallows over it.

For reference purposes, the current level of carbon dioxide in the atmosphere is about 380 parts per million. The EPA estimates that if no action is taken to curb CO2 emissions, the atmospheric concentration of CO2 would be 718 ppm by 2095.

If the Bingaman-Specter bill were implemented, however, the EPA estimates that CO2 levels would be 695 ppm — a whopping reduction of 23 ppm….

Although the EPA didn’t pursue its analysis that far, figuring out the implications are readily doable using the assumptions and formulas of the United Nations’ Intergovernmental Panel on Climate Change. Under the no-action scenario (718-to-695 ppm), the IPCC formulas indicate that the multitrillion-dollar Bingaman-Specter bill might reduce average global temperature by 0.13 degrees Celsius.

Under the maximum regulation scenario (514-to-491 ppm), Bingaman-Specter might reduce average global temperature by 0.18 degrees Celsius. Actual temperature reductions are likely to be less since these estimates rely on the IPCC’s alarmist-friendly assumptions and formulas.

By the way, the figure of 718ppm by 2095 is wildly overstated.  CO2 increased about 90ppm in the last 120 years, and it take wildly aggresive forecats to have it increase by 340ppm in the next 75-80 years.  More on that topic here.