Clathrate (hydrate) gun hypothesis stirred quite the controversy when it was posed in 2003. It stated that methane hydrates – frozen water cages containing methane gas found below the ocean floor – can melt due to increasing ocean temperatures.

Scientists have calculated that the present day ice sheets keep vast amounts of climate gas methane in check. Ice sheets are heavy and cold, providing pressure and temperatures that contain methane in form of ice-like substance called gas hydrate. If the ice sheets retreat the weight of the ice will be lifted from the ocean…