Unexplained Influxes of Carbon in the Greenland Sea May Have Consequences for the Future Nature doi: 10.1038/d41586-018-06097-x Relaximatic The mystery of missing carbon Scientists have discovered that tonnes of unaccounted-for carbon is entering the Greenland Sea due to incomplete CO2 emission tracking. They argue that this ghostly disappearance of carbon has explicit and latent impacts along with its own challenges as their part of in a deep investigation.
Chasing the Elusive Carbon
Accurate tracking of global CO2 emissions is integral to emission treaties and global carbon budgets, but scientists have long struggled with a troubling discrepancy.
To find out what has been missing, we have left it to Professor Are Olsen and his colleagues at the Bjerknes Centre and the Geophysical Institute at University of Bergen. The findings, which appear in the Journal of Geophysical Research: Oceans, reveal a surprising discovery, that many hundreds of millions – if not billions – of tons of carbon trapped in the shallows and sediments have been sheltered from human interference for so long.
The find was the result of a detailed quest that started with a research cruise in 2002. The researchers discovered that the distribution of carbon in the Greenland Sea was not as they had anticipated: instead of being most abundant in deeper, older layers, which would be consistent with long residence times, it was actually located primarily in younger, fresher waters. This indicated that how carbon was moving within, and being stored across the system had changed at its core.
The Phantom Blot Revealed
Olsen and his team of researchers set out to find the carbon’s origins. Using those results, the researchers eliminated a sea creature decomposition source for nitrogen, because they did not see accompanying predicted changes in nitrates or oxygen.
Instead, the team determined that the additional carbon came from greater uptake of CO2 into seawater as a result of anthropogenic pollution, and the more efficient delivery of this carbon to depths in the Greenland Sea.
Changes in ocean circulation, especially enhanced downwelling in the Greenland Sea, have been a critical factor driving the carbon sequestration described by the team. The water that used to be at the surface for decades is now being rapidly pulled down several hundred meters to depths of 1,500 or even 2,000 meters within a few years, and with it the carbon that has been taken up from the atmosphere.
The finding, reported in the journal Science Advances on 1 March, offers an important piece of the puzzle when it comes to understanding the intertwined dynamics of ocean and earth in relation to the global carbon cycle. It serves as a cautionary tale for the need to track these changes in order to be able to properly account for CO2 emissions and their ultimate fate.
Conclusion
Finding this ‘ghost signature’ of carbon in the remote Greenland Sea proves to be a timely reminder for both scientists and policy makers. It highlights both the serious deficiencies in current global CO2 tracking, and the importance of measuring emissions from their source to where they end up.
Although the marine carbon stored beneath the surface of the Greenland Sea may be beyond current human reach, this newfound vulnerability underscores new areas for investigation and potential intervention. And, in a world where change is inevitable and drastic changes are unavoidable, understanding the processes that regulate carbon in Earth´s system may help to better predict what strategies will increase greenhouse gas emissions and to make actions more sustainable.
