“If we’re part of the problem, we need to be part of the solution.” That’s the thinking that drove one of the year’s most ambitious ideas to change fast food production as we know it, Burger King’s “Cows Menu.”

In 2017, agency We Believers had approached the restaurant chain with the proposal to alter cows’ diets to reduce the methane in their burps and farts and ultimately help curb the fast food giant’s own contributions to climate change. After working extensively with top environmental scientists for more than two years, they then discovered that adding 100 grams of lemongrass leaves to the bovines' daily feed in the final four months of their lives could then reduce their methane emissions by up to 33 percent.

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That led to Burger King's first-ever Reduced Methane Emissions Beef Whoppers, which sold in BK restaurants in Austin, L.A., Miami, New York and Portland. The new burgers were promoted in a whimsical, music-video style film directed by Michel Gondry, and though the planet-friendly beef Whoppers were available for only a limited time, Burger King made its research open source so that other chains could access and implement it.

The effort earned Burger King 12.5 billion global impressions and led to a 200% increase in consumer perception of BK as a sustainable brand. Perhaps more important, the effort is expanding globally with more pilots in the U.S., Austria, Ireland, Mexico and Brazil, as well as partnerships with some of the world’s largest meat producers, including JBS, GUSI and KEPAK.