The fast food company claimed, based on an unfinished study, that by feeding their cows lemongrass, they’re reducing methane emissions from their burgers by 30%. Methane is a potent greenhouse gas and cattle for meat and dairy is one of the main sources of this pollution. Contrary to the adverts’ claim, methane from cows primarily comes from burps, not flatulence.

Scientists who examined the claim showed that the feed additive, in this case lemongrass, is only given to cows in the final months before slaughter when they’re in feedlots to be fattened up. As a result, a whole lifetime of emissions aren’t included, making the real emissions reductions more like 3%.

As a major global fast food company specialising in beef, 3% reduction from burgers at a very limited number of test locations is a drop in the ocean and the development of an advert specifically for this small-scale trial is a clear  overinflation of green claims.

Burger King pulled the ad after backlash but the message and video are still publicly available.