A Spectrum of Challenges

“Even in the largest and oldest national parks … most often the serious ecosystem stressors … are not so much from tourism and the interaction of park visitors with nature but represent forces operating at regional to global scales.”
—Gary E. Davis, David M. Graber, and Steven A. Acker
Source: Davis, G. E., D. M. Graber, and S. A. Acker. 2003. National parks as scientific benchmark standards for the biosphere: Or, how are you going to tell how it used to be, when there’s nothing left to see? Pages 129–140 in D. Harmon and A. D. Putney, editors. The Full Value of Parks: From Economics to the Intangible. Rowman and Littlefield, Lanham, Maryland.

The National Park Service is grappling with numerous regional and global environmental issues that affect the preservation and management of park natural resources. Topping this list are climate change and related rising sea level, coastal erosion, changes in local and regional precipitation, and flooding; air and water pollution; depletion of marine resources; introductions of nonnative diseases and organisms; and land-cover change. Understanding how park resources respond to these phenomena, whether those changes are within the range of normal variability, and when and how to intervene to prevent impairment of park resources, if it is even possible, is a key information need of the National Park Service today. By detecting change in the condition of park resources, resource monitoring is emerging as a critical tool for managers to use in filling this information gap. Other research is needed, too, to address this broad spectrum of challenges, as are effective policies and performance measures, consultation strategies, interagency cooperation, and enforcement of regulations. The articles that follow offer interesting glimpses into some of these complex, far-reaching environmental issues and the role that science, policy, legislation, leadership, and partnerships are playing in the understanding and management of these issues in the National Park System. 

Named glaciers occur in 18 parks in the National Park System, primarily in Alaska, with more than half of that state’s 50,000 or more glaciers located in national parks. In the lower 48 states, glaciers occur in nine park units, with more than 95% of those found at North Cascades National Park (Washington).

Glacier mass peaked at the height of the Little Ice Age, from approximately 1750 to 1850. Since then, Glacier Bay National Park (Alaska) alone has lost more ice than any other place in North America— approximately 600 cubic miles (2,500 cu km) in about 250 years, an amount that would cover the state 6 feet (1.8 m) deep. Ecological effects of this tremendous loss of ice include the rapid invasion of plant species to newly exposed land and the transformation of the landscape from a glacier-filled valley to a fjord as ice melts, or from a fjord to a river as the fjord fills with sediments. Additionally, this ice unloading at Glacier Bay is responsible for the world’s fastest rate of vertical land rise—approximately 11.5 feet (3.5 m) per century. Tectonic plates in the Earth’s crust can shift more easily once relieved of the tremendous weight of the ice, potentially triggering earthquakes.

It is extraordinarily difficult to distinguish the normal (background) rate of glacial decay (and growth) over the past 250 years or more from rates over the past century, which might be accelerated and reflect large-scale climate change related to carbon dioxide and other greenhouse gas emissions in the atmosphere, or could simply be related to local or regional climate change.