Measure Carbon Footprint with a Carbon Intensity (CI) Score

corn stalks

Every farm or ranch has a carbon footprint. One way to measure your footprint is with a carbon intensity (CI) score.

What is a carbon intensity score?

A CI score estimates the carbon footprint, or the greenhouse gas emissions, associated with the production of a commodity, i.e., corn. The lower the score, the smaller your carbon footprint – and potentially, the greater the opportunity to benefit financially.

Increasingly, producers are asked to provide their CI score. Ethanol plants are particularly interested in CI scores; they are seeking to reduce their own carbon footprint to qualify for the federal tax credit 45Z. Purchasing grain from producers with low CI scores is one way ethanol plants hope to reduce their overall footprint.

How are carbon intensity scores calculated?   

The Greenhouse Gases, Regulated Emissions and Energy Use in Technologies (GREET) model, developed by the U.S. Department of Energy, is used for calculating CI scores. Some public institutions and private companies offer calculators at no cost. Producers also can hire companies to calculate and certify their scores. These offerings may or may not be using a simplified version of the GREET model, potentially impacting the accuracy of your CI score estimate.

Scores are based on several variables, including yields, the use of cover crops, manure and fertilizer, and tillage practices.

What is a good carbon intensity score?

A CI score of 0 is carbon neutrality. The lower the score, the more attractive your bushels to end users. The degree to which you can lower your score depends on a combination of factors, including soil type and soil health practices. Consulting with experts in carbon sequestration can help you understand your potential improvement.

The estimated national average CI score for corn is 29.1g GHG/MJ, measured with units specifically for ethanol production. Anything below this threshold generates a tax credit for the ethanol plant, according to Iowa State University (ISU). 

How to improve carbon intensity scores?

Higher yields reduce the score by spreading emissions across more bushels. Producers also can see improvements by planting cover crops, reducing tillage and/or their use of synthetic fertilizer, fuel and chemicals.  

How does a carbon intensity score benefit producers?

This is an emerging market, and the benefits to producers and end users has yet to be fully realized. Much of the current focus is on pass-through revenues farmers could receive from ethanol plants that buy their low-carbon grain to qualify for the 45Z tax credit, the rules for which have not been released.

Producers who use ISU’s free tool for scoring their carbon intensity receive two projections:

  • The dollar amount that ethanol plants would obtain from using corn supplied by the farmer as feedstock.
  • The extra-revenue the farmer could receive from the ethanol plant, depending on the share of the tax credit pass-through.