Britain's Prince Charles is supporting a plan to put masks on cows.

This mask uses new technology to reduce the emissions of greenhouse gases. It catches the methane burped out by cows, before turning that gas into harmless carbon dioxide and water.

About nine tenths of the methane emitted by a cow comes from its mouth and nostrils, not from its bottom! And it's all this methane that is adding to climate change.

The mask rests on the cow's head and captures all methane the cow breathes out. The gas then moves through a tiny converter, where it is turned into water and carbon dioxide.

In a design competition, this invention won one of the four top prizes.