Traveled by air in the U.S. lately? Airports and airplanes are packed to the gills. Unruly passengers are making the nightly news and becoming YouTube sensations. Jet fuel shortages are popping up. But there are other developments in air travel too, including a push by the global airline industry to rein in its greenhouse gas emissions. And the heart of that movement is sustainable aviation fuel, or SAF. While the blending of SAF with conventional jet fuel is not mandated in the U.S., the alternative fuel is gaining altitude, in part because it can generate layers of credits that can be utilized in various renewable fuel trading programs. In today’s blog, we look at the current status of renewable fuel in the U.S. aviation sector.