Cows are polluting our atmosphere.
No really. Cows account for more than a third of all methane emissions in the UK according to the Environmental Change Institute at the University of Oxford.
The greenhouse gas traps 25 times more heat in the atmosphere than carbon dioxide.
But it's not farting that's the problem, it's cow burps.
Cows and other animals such as sheep, goats, deer and buffalo are known as ruminant animals which use a compartment of their stomach (the rumen) to break down hard fibres such as grass to prepare it for digestion.
This fermentation process creates methane gas which is then mostly belched out again.
Methane produced by other means (such as the fermentation of organic matter in landfill) can be captured and used to create electricity and heat.
The US has more than 500 landfill to energy projects which power hundreds of thousands of homes.
In 2009, Germany produced enough biogas to power 3.5 million homes and Sweden has a bio-gas operated train.
Harnessing the gas is not so easy with cows though.
Scientists in Argentina have created a method of using the gas, directly from the cow's stomach as it grazes, but it means the poor thing has to walk around with a huge harness and a tank.
There are an estimated 1.5 billion cows in the world, so to fit that to every cow and convert it into a useable gas, well, that's a lot of work.
But a group of scientists in the United States, where cow burps account for over a quarter of methane emissions, think they've come up with a better plan.
They have discovered that adding a compound to cow feed called 3-nitrooxypropanol, or 3NOP to us normal people, the methane gas in the burps is reduced by about 30%.
Not only that, but the milk production is unaffected and the cows put on more weight meaning they derive more energy from the food and presumably provide more burgers.