The Arctic Ocean could become a critical laboratory for understanding the process of climate change, an early warning system for alterations that will affect the entire Earth.
Carin J. Ashjian, Senior Scientist - Woods Hole Oceanographic Institution
James G. Bellingham, Director, Center for Marine Robotics - Woods Hole Oceanographic Institution
Photo by Chris Linder, Woods Hole Oceanographic Institution
Understanding the impacts of climate change on the Arctic Ocean is one of the great challenges of the 21st century. The Arctic has remained a truly hidden ocean, veiled by its ice sheet nearly year-round. Its harsh conditions and remote location have left it largely unexplored—the last ocean region to give up its secrets to science. Indeed, it’s been 20 years since the last major effort to measure biological activity along a transect of the
This ignorance could be costly, however, as the Arctic is changing rapidly. For one thing, atmospheric warming from climate change at polar latitudes is double that of lower latitudes. As a result, more and more of the Arctic sea ice now melts off during the summer, and when it refreezes in winter, the ice is thinner. By some estimates, the summer Arctic could be effectively ice-free in two or three decades. That in turn will bring a host of changes, some of which are already starting—more human activity from shipping, commercial fishing, tourism, and oil and mineral exploration, increased coastal erosion, stormier weather, and potentially large changes to the marine ecosystem. The end of the summer sea ice will also likely mean the end for polar bears and other species that depend on it for access to fishing.
At a less visible level, the end of the sea ice will eliminate the algae that grow on its lower surface and may also diminish native plankton, altering the ocean’s biological productivity and disrupting the marine food chain. The Arctic is also more sensitive than other oceans to increasing acidification from higher levels of dissolved carbon dioxide.
These changes make the Arctic a critical laboratory in which to study climate change—in effect, a place where we can understand and document the linkages between global warming and the physical and chemical changes that in turn drive ecosystem change. However, understanding of the Arctic is sparse because it has been difficult and expensive to mount expeditions in the summer; during the winter, the region has been effectively inaccessible. We don’t even have a baseline for the Arctic against which to measure change, let alone the kind of continuous monitoring and observing tools that are needed to understand processes and measure rates of change.
Given that we have only one Earth, that we
continue to use carbon-based fuels that cause
warming, and we’re uncertain about how climate
change will unfold, the Arctic provides a window
to the future that funding can open.
The basic research challenge is thus to identify the present state of the Arctic marine system, explore system responses to climate change, and identify and predict ongoing and future changes.
That’s important, because as climate change accelerates, many of those changes and impacts will happen in latitudes where people live too. Moreover, changes in the Arctic have impact elsewhere. Melting polar ice sheets, such as the Greenland Ice Sheet, accelerate rising sea levels. Warming temperatures in the Arctic modify atmospheric patterns, particularly the high altitude jet stream that flows from west to east around the earth, with direct impacts on weather across the Northern Hemisphere. One theory is that the jet stream will exhibit greater meanders, driving greater extremes in temperature and drought for the United States and Europe. The unseasonably warm weather in Alaska and Boston’s record snow falls this past winter might be examples of such meandering. A warmer Arctic will also mean thawing permafrost, which not only increases local coastal erosion and run-off of organic materials into the ocean, but also releases methane—a very potent greenhouse gas—to the atmosphere. In effect, thawing permafrost creates a positive feedback loop: the warmer it gets in the Arctic, the more atmospheric warming accelerates.
That makes the Arctic an invaluable laboratory, as well as an early warning system for climate change —if we make the effort to pay attention and understand.