Your Carbon Footprint Doesn’t Matter

We have all heard scary scenarios about global warming. We therefore propose to limit our carbon dioxide emissions, assuming that they are responsible for the warming. So, the central question is: How much carbon dioxide does it take to theoretically raise global temperatures by 1 degree C?

That number can be gleaned from global emissions reports and IPCC scenarios.

Based on data from the Carbon Dioxide Information Analysis Center (DOE) we see that it takes about 15,700 million metric tonnes (mmt) of CO2 to raise atmospheric concentration by 1 part per million by volume (ppmv).

In 2000, mean atmospheric CO2 concentration was 368 ppmv (NOAA global index).

The “let’s do nothing” scenario of the IPCC Fourth Assessment Report (2007) predicts CO2 concentration will rise to 836 ppmv by 2100– a 468 ppmv rise. In the same scenario, the IPCC predicts a temperature rise of 3.4 degrees C. Therefore, under that assumption, to get a 1 degree C temperature rise requires a 140 ppmv rise in atmospheric CO2 concentration (468/3.4 =140).

So, simple arithmetic shows that to get a 1 degree C temperature rise requires carbon dioxide emissions of 2,198,000 mmt. (15,700 mmt/ppmv x 140 ppmv/ C = 2,198,000 mmt of CO2 ). That’s 2 million million tonnes of CO2.

According to the EPA, total human CO2 emissions in the U.S., from all sources, including power plants, industry, automobiles etc. were 6,103 million metric tonnes in 2007. If we stopped all U.S. emissions it could theoretically prevent a temperature rise of 0.003 C. (6,103/2,000,000 = 0.003 C.)

You can do your part; just stop driving your car. The average family car puts out 5.5 tons of CO2 annually and is theoretically responsible for a temperature rise of 0.00000000000311ºC, three one-hundred-billionths of a degree. You can be so proud.

The calculation above ignores the fact that 98.5% of all carbon dioxide emissions are reabsorbed. So that actual emissions would have to be 146 million million tonnes to get a 1 C temperature rise, i.e., if we stopped all U.S. emissions it would really prevent a temperature rise of just 0.00004 C. But it will take even more than that because the effect of CO2 concentration is logarithmic, not linear as assumed above.

Now do you see how stupid Cap & Trades schemes are? Why are we proposing to spend billions or even trillions of dollars on a temperature change we can’t even measure?

Bottom Line:

Human carbon dioxide emissions do not produce a significant change in temperature. We should not be wasting resources trying to control them. If you think differently, then provide some physical evidence to the contrary. IPCC climate models don’t count because they are just speculative computer games.


See similar calculations from Paul Knappenberger of CATO: