GoodFuels

Nonsense Percents

Here’s a riddle for you. When does 61% become 16%?

When you are talking about the lifecycle analysis of greenhouse gas emissions for ethanol as calculated by the EPA under its proposed rulemaking for the Renewable Fuels Standard, the correct answer is when you add in presumed international indirect land use changes.

According to the Renewable Fuels Association, if you just compare “apples to apples” - that is, the direct impacts of corn ethanol’s carbon footprint compared to petroleum, ethanol is 61 percent better than gasoline at reducing greenhouse gas emissions. However, when “international land use changes” are factored into the equation, you get 16 percent - a difference of a whopping 45 percent.

RFA VP for Research Geoff Cooper explains, using one of the many tables included in the 800+ page rule promulgated by EPA that splits out the emissions by phase for both the gasoline baseline and a dry mill corn ethanol plant producing dried distillers grains. “They look at the emissions by phase from the net domestic agricultural phase, international agriculture, domestic land use change, international land use change, fuel production and transportation of fuel and feedstock,” Cooper said during a press conference after the rule was released. “When you total all of those up and subtract the international land use change emissions out of there, that’s where the 61 percent reduction comes from.”

Listen to Geoff explain here:

That is because the international land use change number is the biggest of all in terms of lifecycle GHG emissions, at over 1.9 million CO2-eq/mmBtu. Take it out and the equation is significantly different.

That’s why there is such a huge concern over the indirect land use change issue. Especially since it is based on a model that assumes specific price levels, crop yields and how much land will be put into agricultural production in countries around the world based solely on the use of a certain amount of biofuels in the United States. There is simply no way those calculations can be foolproof accurate. It therefore stands to reason that any inaccurate and unproven model should not be used to penalize ethanol to the tune of 45 percentage points, which puts it four points below the required 20 percent threshold for improvement of greenhouse gas emissions.

If you have the time or the inclination, take a look at the EPA’s proposal. The link here is to the PDF of a 549 page document on the rulemaking, not the 800+ version that Geoff references in his comments. The table he refers to is on page 315 of this document. The entire section on lifecycle analysis starts on page 268.