MIT Technology Review reports:

Eliminating carbon pollution from aviation is one of the most challenging parts of the climate puzzle, simply because large commercial airlines are too heavy and need too much power during takeoff for today’s batteries to do the job.

But one way that companies and governments are striving to make some progress is through the use of various types of sustainable aviation fuels (SAFs), which are derived from non-petroleum sources and promise to be less polluting than standard jet fuel.

This week, the US announced a push to help its biggest commercial crop, corn, become a major feedstock for SAFs.

Federal guidelines announced on April 30 provide a pathway for ethanol producers to earn SAF tax credits within the Inflation Reduction Act, President Biden’s signature climate law, when the fuel is produced from corn or soy grown on farms that adopt certain sustainable agricultural practices.

It’s a limited pilot program, since the subsidy itself expires at the end of this year. But it could set the template for programs in the future that may help ethanol producers generate more and more SAFs, as the nation strives to produce billions of gallons of those fuels per year by 2030.

Consequently, the so-called Climate Smart Agricultural program has already sounded alarm bells among some observers, who fear that the federal government is both overestimating the emissions benefits of ethanol and assigning too much credit to the agricultural practices in question. Those include cover crops, no-till techniques that minimize soil disturbances, and use of “enhanced-efficiency fertilizers,” which are designed to increase uptake by plants and thus reduce runoff into the environment. [Continue reading…]