Reassessing Conservation Goals in a Changing Climate

Abstract

Climate change poses a hierarchy of significant challenges for conservation policy. First, the sheer scale of climate change calls for conservation efforts to be vastly stepped up. Second, the pace and extent of expected climate change will probably undermine the effectiveness of traditional conservation tools focused on protecting designated areas from human intrusion. The search for novel conservation strategies that will stand up to global shifts in climate highlights a third challenge: New conditions and new tools require a reassessment of our conservation goals. This third challenge has so far not been the subject of much debate, but merits closer and more systematic attention. The debate may be uncomfortable, but avoiding it complicates the tasks of prioritizing conservation efforts and choosing conservation tools. More important, the failure to explicitly identify conservation goals that acknowledge climate change is likely to lead to failure to achieve those goals.

The threat of climate change to conservation policy is daunting. Climate change is altering habitats on a grand scale. Species around the world are shifting their ranges to accommodate warming trends. Under any reasonable projection of greenhouse gas emissions, the rate of change will accelerate in coming decades. For species with small populations or specialized habitat requirements, climate change poses special challenges. Although the U.S. Fish and Wildlife Service recently declined to list it as endangered or threatened, the American pika remains an excellent example. The pika, a heat-sensitive mammal that is native to the mountaintops of the American West, can only move so far uphill and cannot migrate to higher or more northerly mountains because it cannot survive the intervening low-elevation habitat. Unfortunately, the magnitude of impending climate change also worsens the prospects for species whose conservation status is not currently directly tied to climatic limitations. For example, the Florida torreya is an endangered conifer found only in a handful of stands along a 35-mile stretch of the Apalachicola River in Florida and Georgia. These populations are currently threatened by an outbreak of a thus-far unidentified disease. Species such as torreya, currently threatened by multiple stresses such as disease, invasive species, and human development, are common throughout the world. Climate change will make their conservation more difficult. Overall, climatic shifts will place at risk many more species, communities, and systems than are currently protected. The magnitude and details of the extinction threat are uncertain, but that uncertainty is itself a challenge to conservation efforts, because conservation planning and implementation are long-term efforts. There is little doubt that future demands will strain the resources available for conservation, which have long been stretched thin.

Keywords: climate change, global warming, adaptation, natural resources, assisted migration, managed relocation, assisted colonization, biodiversity, endangered species, ecosystem management, adaptive management