A "Starter" Carbon Tax Shift

CTC’s proposed national carbon tax, $37 per ton of carbon ramped up each year for at
least 10 years, would reduce emissions by almost 4% annually — more than 30% by 2017.

Dan says

July 27, 2009 at 11:26 pm

Nick,

Why do you introduce confusion into a subject that is hard enough for most people to grasp without your mis-calculations?

In the greenhouse gas business it has become the usual practice to express quantities of greenhouse gases in terms of metric tonnes of carbon dioxide (or its equivalent). So, why do you stick with tonnes of carbon and then do the calculations backward?

A price of $37 per tonne of carbon is equivalent to $136 per tonne of CO2 because a molecule of CO2 has a mass that is 3.67 times that of the carbon item it contains. In your calculation of the effect of a $37/tonne carbon tax, you apparently divided, instead of multiplying, by 3.67 to get $10 per tonne carbon dioxide. About 100 gallons of gasoline emits a tonne of carbon dioxide when burned (actually it takes a bit more than 100 gallons to emit a tonne, but it is reasonable to round to 100 in these discussions).

So, a price of $10 per tonne of carbon dioxide will amount to about ten cents per gallon of gasoline. But, a price of $37 per tonne of carbon, which is equivalent to $136 per tonne of carbon dioxide, will add about $1.20 to $1.30 to a gallon of gasoline.

You made the same major error in calculating the effect on electricity prices; which is not surprising as errors, once made, tend to get made over and over. Here are my calculations:

Assume a price of $10 per tonne of carbon dioxide (which would be $2.72 per tonne of carbon). Then take the average carbon dioxide intensity of the US power plant fleet. I think this is about 0.6 tonnes of carbon dioxide per MWh (0.6 kg CO2 per kWh). That yields $6.00 per MWh or 0.6 cents per kWh. You must have used a carbon intensity for power generation of about 0.7 tonne CO2 per MWh. I won’t argue on that point.

Comments