The Arctic Ocean is a methane sink, but Alaska is now a CO2 red zone

9 May 2017

Research vessel Helmer Hanssen of the Arctic University of Norway off the Svalbard Islands. Image: Randall Hyman/USGS

While a study has found that the Arctic Ocean absorbs enough CO2 to offset methane emissions, Alaska is heading towards ecological disaster.

Although the existence of climate change as a human construct is largely supported within the scientific community, new findings from two separate studies in the Arctic region show that nothing is ever straightforward.

According to the United States Geological Survey (USGS), research conducted with German and Norwegian researchers has found that the world’s most northerly ocean is a giant vacuum for atmospheric CO2.

Undertaken near Norway’s Svalbard Islands, the study analysed the water near the surface of the Arctic Ocean. While it emits harmful emissions of methane, the ocean’s ability to absorb CO2 far exceeded the team’s estimates.

Based on the findings, the Arctic Ocean absorbs 2,000 times more CO2 from the atmosphere than the amount of methane emitted – enough to offset any potential damage caused by the gas.

A possible cause could be the abundance of photosynthetic algae, which are more active near the surface of the ocean, overlying the areas where methane seeps from the sea floor.

Methane seeps could be cool

Previous research has shown that when cold, nutrient-rich waters come up from the depths, algae near the surface can use these nutrients to enhance their photosynthetic processes, resulting in more CO2 being absorbed from the atmosphere.

However, this study is the first to make the observation where methane-rich waters rise to the surface.

“If what we observed near Svalbard occurs more broadly at similar locations around the world, it could mean that methane seeps have a net cooling effect on climate, not a warming effect as we previously thought,” said USGS biogeochemist, John Pohlman.

“We are looking forward to testing the hypothesis that shallow-water methane seeps are net greenhouse gas sinks in other locations.”

Fears for Alaska

Meanwhile, there was less reason to be positive in the Alaskan tundra, where new research shows that the region is emitting more CO2 than it is absorbing, prompting fears of an ecological disaster.

According to a study published in the Proceedings of the National Academy of Sciences, there was a 73pc rise in CO2 emissions between 1975 and 2015 during the winter months.

One potential cause (aside from human pollution) is the exposure of decomposed vegetation – previously trapped in permafrost – to the atmosphere after three years of record high temperatures in the region.

“A lot of models were predicting this thawing would happen, but not for another 50 to 100 years – we didn’t think it would happen this quickly,” said Róisín Commane, lead author of the research.

Colm Gorey was a senior journalist with Silicon Republic