I often feel guilt about my carbon footprint: each and every time I'm in a car and I have to stop to fill the tank; when I find myself mindlessly snacking on a granola bar that turns out to contain, to my chagrin, habitat-destroying corn, soy, or palm oil; that moment when I slice into a juicy, perfectly seared steak, only to have to repress the knowledge that the 500 liters of methane gas produced by just one cow each day traps 21 times more heat in the environment than carbon dioxide does. My existential dread, though, reaches its apex when I step on board a flight and consider the thousands of gallons of fuel my plane will burn through over the course of my trip.
Commercial airline travel is one of the biggest contributors to climate change, accounting for an estimated 4 to 9 percent of all human-generated climatic impact on the environment. For the average person, air travel is the most serious environmental sin they'll commit—often repeatedly—over their lifetime. One round-trip flight from New York to Europe or to San Francisco creates a warming effect equivalent to two or three tons of carbon dioxide per person; take five of those in a year, and your flight miles will account for about three quarters of the 19 tons of carbon dioxide that the average American generates each year.
On Wednesday, the Environmental Protection Agency addressed airline travel's massive environmental impact, announcing its intention to regulate the industry's emissions over the next few years. Planes are going to have to run on cleaner-burning fuels, and scientists are hard at work developing these fuels from some surprising sources, including oils from plants such as tobacco, peanuts, and pennycress, and fats from animals including pigs, chickens, and cows. Within a couple of months, some US flights will already be powered by these alternative biofuels.
The EPA's recent announcement came as no surprise to Steve Csonka, executive director of the Commercial Aviation Alternative Fuels Initiative. For the past eight years, his agency has been researching and testing a variety of biofuels, many of which, Csonka said, hold great promise for reducing flights' overall carbon footprint.
"With the fuels that we are looking at, we can get between 50 and 90 percent reductions in net carbon," he said.
Biofuels, Csonka explained, can be developed from a variety of sources, ranging from natural gas to alcohol to cellulose that's hydrolyzed from the inedible parts of plants. An area that holds particular promise, he said, is animal fat, which can be processed into clean-burning fuel.
"The process is pretty robust, and there are different manufacturers who are playing in this space," Csonka said. "We are primarily talking about product that's coming out of slaughterhouses, from the first processing that occurs prior to finished meat."
AltAir Fuels is a company based in the LA area that's currently retrofitting a Paramount, California tallow refinery to produce jet fuel from beef fat. The company has announced a partnership with United Airlines, which has agreed to buy 15 million gallons of lower-carbon, renewable jet fuel and green diesel fuel over a three-year period, with the option to purchase more. AltAir expects to begin delivering five million gallons of renewable jet fuel per year to United starting this year, and the airline will use the biofuel on flights operating out of its LA hub. A company representative, who provided information on background since the plant is not yet operational, said that beef tallow fuel is a "drop-in diesel," meaning it can be directly substituted, gallon-for-gallon, for traditional petroleum-based diesel.
As Csonka of CAAFI explained, the reason biofuels can be considered "cleaner" than traditional petroleum gas is not because they produce less carbon, but because they make use of available carbon, as opposed to drawing more of it from the earth.
"From the carbon dioxide perspective, these fuels are identical. So if I burn a gallon of jet fuel and I burn a gallon of HEFA fuel, the carbon dioxide that comes out of the tailpipe of the airplane is identical," he said. "The difference comes from the fact that I've produced the synthetic or renewable jet fuel without actually pulling additional carbon molecules out of the ground, or I did it at a substantially reduced level versus what I would have had to pull out of the ground if I just wanted to make petroleum-based jet fuel."
The AltAir representative said that construction on the Altair plant is finishing up, and that they're a couple of months away from initial production of beef tallow jet fuel. Csonka, of CAAFI, summarized the situation:
"Within 30 to 60 days, if you are flying out of LA on United Airlines, there is a chance that there will be HEFA renewable fuel in your fuel tank."