Euroviews. Every time you blame cows for climate change, an oil executive laughs

Given the press, you’d be forgiven for thinking that reducing cattle numbers and moving to a plant-based diet is a climate solution up there with electric vehicles and offshore wind. 

Billions of dollars and euros and celebrity endorsements have been invested in plant-based and alternative protein startups. “Cows create global warming” is a truism of our time, shared by almost all right-thinking people.

The emerging truth appears different. Not only is the climate impact of cattle confused and overblown — properly managed, grazing cows and sheep can be a climate and biodiversity solution. 

Meanwhile, the controversy takes attention away from real priorities: cutting dependence on fossil fuels and fixing farming to restore our landscapes and countryside.

The charge sheet: ruminants like cows and sheep burp methane, a gas 30 times more "greenhousey" than CO2. 

The Amazon rainforest is being denuded for beef. A hamburger uses almost 3 tonnes of water. 

The opportunity cost of the vast tracts of land used for pasture, or growing fodder is too high; it could be used to grow food for humans instead, or even better, rewilded, sequestering gigatons of carbon. Write in if I missed any.

To understand the warming impact of ruminants we need to distinguish methane stocks (the amount in the atmosphere) versus flows (movements in and out of the atmosphere). Cow and sheep burps are part of a cyclical flow. 

The methane, or CH4, comes from fermenting grass and cellulose in their rumen. The carbon, or C in the CH4, came from the plants they ate, which in turn came from atmospheric CO2 via photosynthesis. 

Once out there, the CH4 eventually breaks down into CO2 again, ready to be photosynthesised. 

It’s not clear that this is a net emission at all.