One of the biggest problems facing agriculture today is what to do about emissions. 

Estimates vary, but livestock are reckoned to be responsible for up to 14 percent of all greenhouse emissions from human activities, with the average cow producing 250-500 litres of methane a day.

AgResearch have been working on giving cows a vaccine against certain gut microbes that are responsible for producing methane.

The more fibre a cow eats, the more methane it produces, but adding legumes and various oils to their diet can be helpful.

However, now researchers at the University of California have found that a small amount of seaweed fed to cows over five months means they produce 82 percent less methane.

Nanogirl Michelle Dickinson joined Francesca Rudkin to explain.

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