California subsidies for dairy cows’ biogas are a lose-lose, campaigners say

The state pumps millions into methane produced by manure - but advocates argue it increases greenhouse gas emissions and encourages factory farming

A coalition of climate, environmental and animal welfare groups is calling for California to remove the huge subsidies provided to dairy farms to turn animal waste into a form of energy called biogas.

Manure, which emits the potent greenhouse gas methane, is a big problem for US farms, and is particularly stark in California, where the dairy industry accounts for nearly half the state's methane emissions.