5 reasons Maine should care about warming Arctic waters – P. Mayewski
Climate Change Institute
This figure shows the temperature departure from average (1979-2000 baseline) for much of the Northern Hemisphere. This is a typical day for winter 2014-2015. While eastern and notably northeastern U.S. are unseasonably cold, the rest of the Northern Hemisphere is unseasonably warm, and the Arctic is dramatically warmer. Greenhouse gas warming has affected the pattern of the jet stream that divides cold and warm air. Data were plotted using the Climate Change Institute Climate ReanalyzerTM software.
We tend not to think that much about the Arctic living in the lower 48. After all, mid-Maine is barely halfway between the Equator and the North Pole.
But the Arctic has and will continue to play a major role in our lives.
Maine has a long history of fishing, shipping and exploration in the Arctic, and the University of Maine has a long tradition of research in the Arctic — spanning the Arctic Ocean and surrounding oceans, the Greenland Ice Sheet and ice cover on the Arctic Islands, marine and terrestrial ecosystem studies, air quality, human dimensions of climate and cultural change and more.
The University of Maine’s Climate Change Institute has been conducting research in the Arctic for many years focused on past, present and future changes in the physical, chemical, biological and social aspects of climate change and the interaction between changes in the Arctic and changes throughout the rest of our hemisphere and planet.
But now more than ever Maine, the United States, North America, the Northern Hemisphere and even the world are being affected by recent changes in climate throughout the Arctic.
Climate, sea and land ice extent, ocean temperature, salinity and currents, atmospheric circulation pathways, and ecosystems have changed in the past in response to natural controls, but human activity has altered the equation through the emission of markedly increased levels of greenhouse gases at highly accelerated levels, relative to at least the last several hundred thousand years.
Greenhouse gases and other human source pollutants — including toxic metals, radioactivity and humanly engineered chemicals — have affected our lives, and the Arctic is an early victim.
The Arctic has fallen prey to significant change because the Arctic Ocean is capped by just a few rapidly declining feet of sea ice that, when melted, if only for portions of the summer season, release heat from the ocean — further accelerating warming.
In addition, the surface of Arctic land ice is experiencing increased warming, including Earth’s second largest ice sheet, the Greenland ice sheet. And the edges of glaciers floating into or in close proximity to the ocean are melting.
Decreased Arctic snow and ice cover are changing the surface color of the Arctic from white (snow and ice), which reflects incoming solar radiation, to darker colors (ocean blues and exposed land cover) that absorb incoming solar radiation, resulting in even more warming.
So what does this all have to do with Maine?
1. Recent melting of even the small number of glaciers, as monitored by Climate Change Institute researchers, demonstrates the potential for significant impact on sea level rise, accompanied by freshening of surrounding seawater as fresh glacier melt enters the ocean. This in turn results in changes in ocean circulation that can impact the Gulf of Maine and its ecosystem. Decay of Greenland coastal glaciers also yields increased iceberg production with impacts on navigation.
2. Research by the Climate Change Institute demonstrates that in recent years dramatic and abrupt regional scale warming has led to a doubling of the summer season over portions of the Arctic. The rate and magnitude of this warming exceeds that of the last several thousand years, making it a very notable, abrupt climate change event. Climate Change Institute researchers have figured prominently in the realization that climate can experience several-degree Fahrenheit changes, massive shifts in water availability, and storminess abruptly (in a year to several years). This is important because before this discovery it was assumed that climate change was slow and linear. Now we know that climate change can operate fast enough and of significant magnitude to impact the course of past civilizations.
3. As a consequence of Arctic warming, the edge of the polar vortex (the cold air region over the high latitudes) is changing, leading to more storms — because cold polar air can push farther south, and warm air can push farther north in the Northern Hemisphere. The intersection of cold and warm air results in unstable, stormy weather. Patterns of the jet stream similar to the one portrayed in the image with this piece have resulted in cold, stormy winters over the northeastern U.S., leaving drought in the western U.S. Note that while the Northeast has been anomalously cold and stormy, the rest of the Northern Hemisphere and in particular the Arctic continue to warm. Even a warming Arctic generates cold air in the winter, and it has to go someplace. Topographic controls have sent it to Maine for our recent winters.
4. Arctic summer sea ice extent and thickness have decreased markedly in recent years. While this situation is creating severe challenges for those who live in the Arctic and Arctic wildlife, in addition to mounting geopolitical issues related to exploitation of Arctic resources, international claims, safety and security, it is also creating new potential for shipping through the Arctic that is more efficient than southerly routes through Central America. All indications are that Arctic summer sea ice will continue to decrease over coming years, and this means that an eastern U.S. ocean port will be needed to accommodate this demand. With good stewardship, this is an important opportunity for Mainers and Maine’s economy.
5. As Arctic permafrost (frozen ground) melts, a new source of greenhouse gases emerges — methane from old buried organic matter — and it is significantly more effective as a greenhouse gas than carbon dioxide. This secondary effect of a warming Arctic, methane release, has the potential to significantly boost warming, magnifying the consequences.
To put climate change in perspective: It affects our health (humans and the ecosystem), our economy (energy, food and water availability), the frequency and magnitude of environmental hazards (storms, droughts, pollutant spills), and it has critical geopolitical implications (opening of the Arctic, unrest stemming from drought, and potential for millions of refugees fleeing flooding, drought and starvation), making it a clear and present security issue.
Maine’s evolving climate will bring with it challenges, but with good planning it will also offer opportunities for increased energy and resource use efficiency, locally developed food production, jobs, and much more.
Paul Andrew Mayewski is director of the Climate Change Institute at the University of Maine.
By Paul Andrew Mayewski, Special to the BDN
April 04, 2015