Frostbites

The Arctic Ocean is presently experiencing changes in ocean temperature and sea ice extent that are unprecedented in the observational time period. To provide context for the current changes, scientists turn to paleo records of past climate to document and study natural variability in the Arctic system. Paleoceanographic records that extend limited Arctic instrumental measurements are central to improving our understanding of sea ice dynamics and ocean warming and for enhancing the predictive capability of models. By coupling paleoceanographic records with modern observations, scientists can also contextualize the rate and magnitude of modern change with the deep past.

Shortly after the beginning of the 21st Century, the Arctic began an environmental transition so extensive that it caught scientists, policymakers, and residents by surprise. The extent and duration of these transitions defines the New Arctic, characterized by the lowest winter maximum in sea ice cover on record for 2017, the persistent and record warming of sea surface temperatures across the Arctic, and the downward trend in total ice mass of the Greenland ice sheet, just to name a few. The unprecedented rate and global reach of these changes highlight the pressing need to prepare for and adapt to the New Arctic.

During a 1979 research cruise in the Bering Sea, Conrad Oozeva, a Native hunter from St. Lawrence Island, shared dozens of Yupik words for sea ice (Fig. 12.1). I recently looked at my notebook from that period and realized that some of those terms—such as tagneghneq (thick, dark, weathered ice)—refer to types of sea ice that are rare or non-existent today. That some of those Yupik terms—probably in use for thousands of years—would become obsolete in just a few decades attests to the rapid pace of change in the Arctic and to the impacts on indigenous peoples (Berman 2004; Oozeva et al. 2004; Ford and Pearce 2010).

Community-based monitoring (CBM) is a broad set of approaches that engage the capacity of community residents in observing and monitoring of a region, e.g., the Arctic (Arctic Council 2015; Johnson et al. 2015). CBM encompasses a continuum of approaches from community-based observing network systems (CBONS), citizen science and observer blogs (Table 11.1).

Ice loss from the Greenland Ice Sheet (see Fig. 3.4 in the essay on the Greenland Ice Sheet) is a principal source of sea level rise. During 2009-2012, the Greenland Ice Sheet lost ~380 Gt of ice per year, contributing ~1.05 mm yr-¹ to sea level rise (Enderlin et al. 2014), compared with a global mean sea level rise of ~3.2 mm yr-¹ during 1993-2010 (IPCC 2013). Ice loss occurs through two primary processes: (1) surface melt and runoff from across the ice sheet, and (2) calving of icebergs into the ocean from marine-terminating outlet glaciers.