It is not just about the ice: a geochemical perspective on the changing Arctic Ocean

Much concern has accompanied the dramatic decrease in area covered by permanent pack ice in the Arctic Ocean during the past two decades. Ice is undeniably the most obvious feature distinguishing the Arctic Ocean, and its loss seizes public and scientific attention like no other tipping point. Beneath that challenging ice surface lies an ocean that is strongly affected by other less-visible factors that also have a large say in how change will occur in this ocean. Especially important to the Arctic Ocean is its connection to the surrounding land, which feeds it fresh water and organic carbon, and the large shelves and enclosed geography that accentuate the importance of these external factors. Like the sea ice, land is changing rapidly due to widespread thawing of permafrost. For the three global risks that have been deeply thought about recently in the context of Arctic Ocean ecosystems (i.e. contaminants, warming, ocean acidification), the Arctic appears to be exceptionally sensitive, sufficiently so that it has been termed a bellwether for each. Here, we examine how the less-visible factors (fresh water, organic carbon cycling) affect the Arctic’s reception of risk and its potential to export risk to the rest of the globe. We conclude that there needs to be a better coordinated effort to collect time series for the terrestrial components cycling within the Arctic Ocean such that we can understand what is happening to the marine components. Copyright The Author(s) 2015