Burning methane hydrate, also known as methane ice or methane clathrate. Methane hydrate consists of a molecule of methane surrounded by a cage of water molecules, which give it a solid ice-like structure. Methane hydrate is found in the very cold and high pressure environments under the arctic permafrost and in marine sediments, where it forms a crystalline solid. It is thought there is approximately 3000 times the volume of methane in hydrates than in the atmosphere, making it a huge potential energy source. However, methane is a greenhouse gas and so any release would contribute towards global warming.