Methane hydrate is a solid form of water containing large amounts of methane, occurring in vast quantity (“2-10x the currently known reserves of conventional natural gas”) on ocean floors. When warmed or depressurized, it turns into water and natural gas. However, there’s a big downside too.
Methane, a “greenhouse” gas, is 10 times more effective than carbon dioxide in causing climate warming.
Like it or not, extraction of methane hydrates will probably happen, let’s hope it’s done sanely and safely.