Last year marked the start of the United Nations Environment Programme’s (UNEP) Decade on Ecosystem Restoration. UNEP et al., Ecosystem Restoration Playbook: A Practical Guide to Healing the Planet, at 3 (2021). This call to recover nature stems largely from society’s remaining tendency to value the short-term gains from environmental degradation over the long-term benefits of environmental preservation. Recent assessment reporting by the Intergovernmental Panel on Climate Change likewise recognizes that unrelenting overexploitation of the world’s natural resources continues and identifies nature-based solutions like ecosystem restoration as an effective means to mitigate carbon emissions and adapt to changing climatic conditions. Intergovernmental Panel on Climate Change, Sixth Assessment Report, at 3-108, 4-92 (2022). Through this decadal movement, UNEP aims to motivate a global effort to prevent, halt, and reverse further ecosystem degradation and loss and to bring attention to ecological restoration as a solution for protecting the world’s future environmental health.
Projects such as the dam removals along the Elwha River on the Olympic Peninsula in Washington state illustrate the potential restoration efforts hold. Under the Elwha River Ecosystem and Fisheries Restoration Act, Pub. L. No. 102-495, 106 Stat. 3173 (1992), the U.S. Congress authorized dam removal to restore the Elwha riverine ecosystem and anadromous fish populations. Since removal, salmon and trout have returned to the river, and scientists have observed watershed-wide restorative effects due to restored natural hydrology, connectivity, and ecosystem functionality, evidencing nature’s ability to recover from landscape-scale alteration. Soc’y for Ecological Restoration, USA: Washington: Elwha Dam Removal and River Restoration (2022).
Other cases, however, demonstrate possible shortcomings of ecological restoration as scientists continue to invent and hone ecosystem recovery methodologies. Saltwater wetland ecosystems, for example, have complex hydrological, ecological, and geomorphic processes, presenting challenges for scientists, natural resource managers, and practitioners endeavoring to recreate them. A recent study assessing salt marsh restoration in the United Kingdom highlights this difficulty, explaining that restored wetland ecosystems may not provide the same number or quality of ecosystem services—the benefits people receive from nature—as natural wetland ecosystems. See C. Chirol et al., Morphological Evolution of Creek Networks in 10 Restored Coastal Wetlands in the UK, 9 Sci. Data 144 (2022); see also Walter V. Reid et al., Ecosystems and Human Well-being: Synthesis, at v (Millennium Ecosystem Assessment 2005) (defining ecosystem services).
Environmental laws in the United States employ ecological restoration as a means to address continual ecosystem degradation and loss from pollution and development. For example, section 404 of the Clean Water Act (CWA), 33 U.S.C. § 1251 et seq., permits the use of compensatory mitigation, meaning compensation for impacts to natural resources by restoring or replacing those impacted resources and their functions that have been lost or impacted, to offset “unavoidable” impacts to wetland, riverine, or other aquatic resources. See 33 C.F.R. § 332.3. Through this process, land use development projects can be mitigated by restoring, creating, enhancing, or (in rare cases) preserving wetlands, streams, or other aquatic resources elsewhere, though usually within the same watershed as the impacted resource. Compensatory Mitigation for Losses of Aquatic Resources, 73 Fed. Reg. 19,594 (Apr. 10, 2008).
Natural resource damages (NRD) sought under the Oil Pollution Act (OPA), 33 U.S.C. § 2701 et seq., and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. § 9601 et seq., also incorporate ecological restoration to fulfill compensatory mitigation requirements. These federal statutes authorize federal and state resource agencies as well as Tribal nations (in a given case, collectively named the “natural resource trustees”) to seek NRD as a remedy when releases of oil or hazardous substances injure, destroy, or cause the loss of public natural resources, such as wildlife, plants, water, and soils. See 33 U.S.C. § 2702(b)(2)(A); 42 U.S.C. § 9607(f). Generally, NRD include (1) the cost of restoring, rehabilitating, replacing, or acquiring the equivalent of the injured natural resources; (2) the value of services the public has lost until resources are restored, rehabilitated, replaced, or acquired, which is termed “compensable value”; and (3) the reasonable cost of performing a damage assessment. 43 C.F.R. § 11.80(b). To determine the compensable value, natural resource trustees use valuation methodologies such as habitat equivalency analysis (HEA), which estimates the lost value of habitat by assessing the services provided by individual resources within the injured ecosystem. See id. § 11.83(c)(2). Practitioners use HEA and other methods to inform the scale of replacement or restoration projects needed to reestablish the services lost due to injury to natural resources. See Kathleen C. Schroder & Nels C. Johnson, How to Put a Price on Nature, Rocky Mt. Min. L. Found. Special Inst.: Advanced Pub. Land Law, at 4–12 (2017).
A key assumption underlying both CWA section 404 permitting and NRD compensatory mitigation schemes is that ecosystems and the natural resources that comprise them are, in fact, replaceable. Additionally, valuation methodologies informing compensatory mitigation under these laws rely on the further assumption that the public is willing to accept a restored ecosystem in the same or a different location in place of the pre-impacted ecosystem. See, e.g., Nat’l Oceanic & Atmospheric Admin., Dep’t of Com., Habitat Equivalency Analysis: An Overview, at 1 (1995). Thus, restoring an ecosystem or resource of the same type as that injured, whether on- or off-site, is viewed equally in value. This approach, however, fails to consider the lost value at the ecosystem and landscape scale. In so doing, compensatory mitigation under the CWA, OPA, or CERCLA can underestimate the overall impact of environmental degradation upon ecosystem functioning and biodiversity, resulting in net losses in ecosystem services over time.
Ecosystem restoration is an indisputably important tool for preserving the future health of the world’s ecosystems, especially in the face of the staggering rate at which natural environments have already been and continue to be degraded and lost. See Andrew J. Plumptre et al., Where Might We Find Ecologically Intact Communities?, 4 Frontiers in Forests & Glob. Change, no. 626635, at 1 (Apr. 15, 2021) (explaining less than 3% of the world’s land remains ecologically intact with healthy wildlife populations and undisturbed habitat). But lessons can be learned from the existing environmental law structure that largely undervalues ecosystems and the services they provide. To realize the goals set by UNEP for this next decade to begin reversing society’s current trends of vast ecosystem degradation and loss, it will be crucial for policymakers and practitioners to understand the intrinsic value of earth’s complex and dynamic ecosystems, which are not so easily replaced.
