Over the past few years, switching to meat alternatives has grown in popularity as folks look to eat less meat for environmental reasons. One of the biggest environmental concerns is the greenhouse gas emissions that livestock production gives off, roughly 65% of which comes from beef, according to the Food and Agricultural Organization of the United Nations (FAO).

People still want to eat meat, though, and research has begun to take shape in how meat production could reduce its own emissions. Some of that research has made its way to Burger King, who is now using it to make "Reduced Methane Emissions Beef" for some of its Whoppers.

Burger King's new beef comes from research that herbs like lemongrass can be used to reduce the amount of emissions that come from enteric fermentation. This means that in cow's stomachs, different kinds of bacteria can ferment what they eat into gases that include methane, and by changing around a cow's diet, you could reduce some of the methane these gut bacteria produce.

Burger King discussed its own test data related to emissions in a press release, which claims that adding 100 grams of lemongrass to cow's diets helps them release less methane as they digest food. BK's Reduced Methane Emissions Beef goes on this diet for three to four months prior to slaughter, which, according to Burger King, can lower methane emissions by an average of 33% per day.

Burger King's own research was conducted in tandem with the Autonomous University of the State of Mexico and U.C. Davis. An independent 2013 study from the Asian-Australasian Journal of Animal Sciences found lemongrass to be effective, but lemongrass in conjunction with supplemental herbs and spices like garlic powder and peppermint could possibly lower emissions even more.

Burger King is taking a big step forward, though, in introducing this kind of beef in its locations, as well as trying to reduce the carbon footprint of its burger production.

Right now, you can get Reduced Methane Emissions Beef Whoppers at select locations in Miami, New York, Austin, Portland, and Los Angeles while supplies last.