So, Mr. Waxman, how much global warming will your bill avert?

The Waxman-Markey cap-and-trade (energy tax) bill aims to reduce U.S. greenhouse gas emissions 20% below 2005 levels by 2020, 42% below by 2030, and 83% below by 2050. The cumulative cost in reduced GDP would likely total trillions of dollars. How much bang would we get for the buck?

Today, on, climate scientist Chip Knappenberger shows by the numbers that the Waxman-Markey bill “will have virtually no impact on the future course of the earth’s climate.”

To calculate the climatic effects of the bill, Chip uses the MAGICC* climate model developed by the National Center for Climate Research, and assumes a climate sensitivity of 3°C (in other words, a doubling of atmospheric greenhouse gas concentrations above pre-industrial levels is assumed to produce 3°C of warming).

MAGICC reveals that an 83% reduction in U.S. emissions “will only produce a global temperature ‘savings’ during the next 50 years of about 0.05ºC.”  Translating a bit, the temperature reduction is nine hundredths of one degree Fahrenheit, or two years of avoided warming.

* Model for the Assessment of Greenhouse-gas Induced Climate Change