Methane is a powerful greenhouse gas, so if large quantities of it are released into the atmosphere it could make climate change even worse.That may be starting to happen as researchers have found 250 plumes of methane bubbles that are rising from the sea bed off Norway.
Vast quantities of methane are trapped as methane hydrate in sediment under the Arctic seabed. Methane hydrate is a frozen substance made up of water and methane, which is stable under high pressure and low temperature. But as temperatures rise, the hydrate is starting to break down which can result in the methane being released.
The lower the temperature is, the less pressure is required to keep the methane hydrate stable. Data collected over 30 years shows that it used to be stable at a depth of 360 metres, but recent evidence shows that it is now stable at depths of over 400 metres. This is probably because this area of the ocean is now 1 C. warmer than it used to be.
Researchers have found that most of the methane is dissolving into the seawater and they have not yet detected any evidence that the gas is breaking the surface and getting into the atmosphere, although they emphasise that this doesn’t mean that it isn’t doing. But even if it’s not getting into the atmosphere, it is making the ocean more acidic, as it is combining with oxygen in the water to form CO2, which in sea water forms carbonic acid.
The full BBC story can be found on their website.
