Sleeping Giants of the Carbon Cycle

Why in NEWS ?

Scientists have found evidence that frozen methane deposits in the Arctic Ocean – known as the “sleeping giants of the carbon cycle” – have started to be released over a large area of the continental slope off the East Siberian coast.

About

• High levels of the potent greenhouse gas have been detected down to a depth of 350 metres in the Laptev Sea near Russia, prompting concern among researchers that a new climate feedback loop may have been triggered that could accelerate the pace of global heating.
• The slope sediments in the Arctic contain a huge quantity of frozen methane and other gases – known as hydrates.
• The international team onboard the Russian research ship R/V Akademik Keldysh said most of the bubbles were currently dissolving in the water but methane levels at the surface were four to eight times what would normally be expected and this was venting into the atmosphere.

Point of Concern

• The discovery of potentially destabilised slope frozen methane raises concerns that a new tipping point has been reached that could increase the speed of global heating.
• With the Arctic temperature now rising more than twice as fast as the global average, the question of when – or even whether – they will be released into the atmosphere has been a matter of considerable uncertainty in climate computer models.
• At one location on the Laptev Sea slope at a depth of about 300 metres they found methane concentrations of up to 1,600 nanomoles per litre, which is 400 times higher than would be expected if the sea and the atmosphere were in equilibrium.
• For the second year in a row, in the shallower parts of the Laptev Sea and East Siberian Sea that are discharging bubble jets of methane, which is reaching the sea surface at levels tens to hundreds of times higher than normal.

Methane

• Though Methane is a clean fuel but it is the most important greenhouse gas after carbon dioxide.
• It is produced from decomposition of animal wastes and biological matter.
• The emission of this gas can be restricted by using animal wastes and biological matter to produce gobar gas (methane).
• Methane has a warming effect 80 times stronger than carbon dioxide over 20 years. The United States Geological Survey has previously listed Arctic hydrate destabilisation as one of four most serious scenarios for abrupt climate change.