Mitigation options for reducing methane emission from ruminant enteric fermentation include genetic selection, immunization, rumen defaunation, diet modification and grazing management, among others.

Scientists found the mix of garlic and citrus extract reduced methane emissions by up to 38 per cent.

This means that a methane emission will have 34 times the impact on temperature of a carbon dioxide emission of the same mass over the following 100 years.

Livestock had been thought to generate around 18 per cent of world methane emissions.

As trapped material decays in reservoirs, methane bubbles are released; tropical locations tend to have more vegetation, and therefore higher methane emissions.