Methane is a potent greenhouse gas, 25 times more powerful than Carbon Dioxide, but thankfully, nowhere near as abundant. Greenhouse gases are gases that trap heat from the sun in the Earth's atmosphere, just like glass traps heat in a greenhouse. Here at sea level, methane is emitted as a byproduct of any number of industries, from landfills and agriculture, to oil and gas resources. The industrial sources of methane are worrying, but of even greater concern are natural sources of methane that have been locked deep under oceans and ice for a very long time. When methane interacts with water at very low temperatures it forms a solid called methane hydrate, a lattice-like structure that traps the methane. Now, at least some of these frozen prisons seem like they're starting to melt.