Climate change is affecting valued resources and ecosystem services in complex ways, as well as challenging existing management practices. While natural resource management has traditionally focused on maintaining or restoring historical conditions, these goals and strategies may no longer be realistic or effective as the climate changes.194 Climate-driven changes are most effectively managed through highly adaptive and proactive approaches that are continually refined to reflect emerging and anticipated impacts of climate change (Ch. 28: Adaptation, Figure 28.1).194 Decision support tools, including scenario planning195,196,197 and structured decision-making,198 can help decision-makers explore broad scenarios of risk and develop actions that account for uncertainty, optimize tradeoffs, and reflect institutional capacity.
Systems that are already degraded or stressed from non-climate stressors have lower adaptive capacity and resilience (Ch. 28: Adaptation, KM 3); therefore, some of the most effective actions that managers can take are to strategically restore and conserve areas that support valued species and habitats. However, these actions will be most effective when they consider future conditions in addition to historical targets.4 New guidance on habitat restoration actions that can help to reduce impacts from climate change199,200,201 is now being incorporated into regional and local restoration plans (Ch. 24: Northwest, KM 2). Limiting the spread of invasive species can also help maintain biodiversity, ecosystem function, and resilience.202,203,204 In 2016, the U.S. Federal Government recommended specific management actions for the early detection and eradication of invasive species.205
Understanding and reestablishing habitat connectivity across terrestrial, freshwater, and marine systems are other key components in helping ecosystems adapt to changing environmental conditions.45,46,201,206 Identifying and conserving climate change refugia (that is, areas relatively buffered from climate change that enable persistence) in ecological corridors can help species stay connected.207,208 For example, areas of particularly cold water have been identified in the Pacific Northwest that, if well-connected and protected from other stressors, could act as critical habitat for temperature-sensitive salmon and trout populations.209,210,211 More active approaches like assisted migration, whereby species are actively moved to more suitable habitats, and genetic rescue, where genetic diversity is introduced to improve fitness in small populations,212 may be considered for species that have limited natural ability to move or that face extreme barriers to movement due to habitat fragmentation and development (Ch. 5: Land Changes, “State of the Sector” and KM 2).124 For any assisted migration, there could be unforeseen and unwanted consequences. Developing policies to analyze and manage the potential consequences of assisted migration would not guarantee successful outcomes, but is likely to minimize unintended consequences.213,214
Climate change impacts have been incorporated into national and regional management plans that seek to mitigate harmful impacts and to address future management challenges, while also accounting for other non-climate stressors. Federal agencies with responsibilities for natural resource management are increasingly considering climate change impacts in their management plans, and many have formulated climate-smart adaptation plans for future resource management (such as the National Oceanic and Atmospheric Administration [NOAA], National Park Service [NPS], and U.S. Fish and Wildlife Service [USFWS]).215,216,217,218,219,220 For example, the National Marine Fisheries Service recognizes climate change as a specific threat to marine resources, has developed regional action plans (e.g., Hare et al. 2016221), and is undertaking regional vulnerability analyses to incorporate climate change impacts in decision-making.129,215,217 Agencies within the Department of the Interior are also increasingly developing and using climate change vulnerability assessments as part of their adaptation planning processes.222 For example, USFWS has considered climate change in listing decisions, biological opinions, and proposed alternative actions under the Endangered Species Act (e.g., USFWS 2008, 2010223,224). In addition, federal agencies have been challenged to develop policies and approaches that consider ecosystem services and related climate impacts within existing planning and decision frameworks.225 For example, ecosystems can be managed to help mitigate climate change through carbon storage on land and in the oceans (Ch. 29: Mitigation, Box 29.1; Ch. 5: Land Changes, KM 1)200,226,227 and to buffer ocean acidification,228 which could help reduce pressure on ecosystems. USFWS has been acquiring and restoring ecosystems to increase biological carbon sequestration since the 1990s.229
At the local and regional levels, efforts to restore ecosystems, increase habitat connectivity, and protect ecosystem services are gaining momentum through collaborations among state and tribal entities, educational institutions, nongovernmental organizations, and partnerships. For example, the Great Lakes Climate Adaptation Network, NOAA’s Great Lakes Integrated Sciences and Assessments Program, the Huron River Watershed Council, and five Great Lakes cities worked together to develop a vulnerability assessment template that incorporates adaptation and climate-smart information into city planning (Ch. 21: Midwest, Case Study “Great Lakes Climate Adaptation Network”). Significant work remains, however, before climate change is comprehensively addressed in natural resource management at local and national scales. Improved projections of climate impacts at local and regional scales would likely improve ecosystem management, as would predictive models to inform effective adaptation strategies.230,231,232 Yet such tools are often hampered by a lack of sufficient data at the appropriate scale.232 In addition, institutional barriers (such as a focus on near-term planning, fixed policies and protocols, jurisdictional restrictions, and an established practice of managing based on historical conditions) have constrained agencies from comprehensively accounting for climate impacts.194 Finally, more rigorous evaluation of adaptation efforts would allow managers to fully assess the effectiveness of proposed adaptation measures.194