Delta Air Lines laid out a new plan to wean its planes off fossil fuels in an effort to address climate change. The goal, the airline said, is for sustainable aviation fuel (SAF) to make up at least 95 percent of its fuel consumption by 2050.
SAF is made from waste or crops through a process that’s supposed to cancel out much of the greenhouse gas emissions a plane produces. It’s not a perfect system and could create new environmental problems. And with very little SAF...