A proposed Sustainable Aviation Fuel tax credit would carve a billion dollars out of California's roads to subsidize aviation fuel. Supporters want it written into the state budget. It sounds green. The experts disagree.
It doesn't make clean fuel. It just moves it.
SAF and renewable diesel come from the same limited feedstocks, often the same facilities. Subsidize one and you simply starve the other.
Any increase in renewable jet fuel production will result in a corresponding decrease in renewable diesel production. U.S. Environmental Protection Agency
Families and truckers pay more.
To keep the roads supplied, California backfills with fossil diesel, and prices climb across gasoline, freight, and rail.
+11–14¢ gasoline · +12¢ diesel
We estimate that both gasoline and diesel prices would rise. Energy Institute at Haas, UC Berkeley
And the climate gains? Negligible.
The supply of feedstock is fixed. Changing where the fuel burns just moves emissions around. It doesn't lower them.
The proposed SAF credit is unlikely to reduce global GHG emissions. California Legislative Analyst's Office