A global scientific consensus has emerged recognizing that climate change and biodiversity loss are two key environmental crises faced by the world.1 Over the past century, anthropogenic climate change has increased global surface temperatures by 1.1°C.2 Estimates show that 1 million species are currently at-risk of extinction with climate change as a leading cause and one that is projected to become even more dominant over upcoming decades.3 Though the effects of climate change are a major driver of the global “decline in nature”,3 many countries have failed to yield imperiled species conservation plans that properly reflect this threat.4–6 Understanding trends and gaps in imperiled species planning can help guide more robust conservation plans to adequately address the threat of climate change for these species. Within the US, discerning the underlying causes for recovery plan deficiencies may reveal where there are shortfalls in the federal agency management system regarding imperiled species. As the effects of climate become more severe, comprehensive conservation planning and implementation will be imperative to protecting imperiled species from extinction.7–9 Understanding and addressing current gaps in planning can help ensure effective recovery action.
Delach et al. (2019) assessed the climate change sensitivity for all 459 animals listed as “endangered” under the Endangered Species Act (ESA) with ranges at least partly within the US or its territories. They also evaluated whether climate change is discussed as a threat and whether agencies described climate-related management action in official documents published by the two federal agencies that implement conservation and recovery actions under the ESA- the US Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS)- from the Act’s inception in 1973 through the end of 2018. They found that 99.8% of the animals listed as endangered species were sensitive to one or more of eight factors potentially indicating sensitivity to climate change, but agencies considered climate change as a threat to only 64% of endangered animals and planned management actions for only 18%.
Delach et al. (2019) noted that both the number of ESA documents published annually and the proportion of those discussing climate change had declined in the first two years of President Donald Trump’s administration. Additionally, the pace of new listings also declined, from an average of 11.4 animal species protected as endangered per year during the Obama administration, to just 2.5 per year during the first half of the Trump Administration.10
The pace of recovery document publication increased starting in 2019. From 1 Jan 2019 through the end of the Trump administration, recovery agencies published 177 five-year reviews, and 20 recovery plans and 90 recovery plan addenda for endangered animal species. From the start of the Biden administration through the end of 2022, agencies published 131 five-year reviews, 53 recovery plans, and 2 amendments for endangered animal species. Some species had multiple documents published in this time frame. We reviewed all documents published in 2019–2022, and several from 2017–2018 that were added to the system after the initial analysis, to determine whether the agencies provided new or updated information regarding climate threats and actions. For each species, we report the most recent document that includes climate change considerations, or the most recently published document if none consider climate change.
We also report an update to Delach et al. (2019) based on all listing changes and documents published through the end 2022. Within this period, six species were downlisted to threatened; eight species were delisted; and thirteen species were newly listed as endangered.
For the newly listed species, we replicated their protocol (see Delach et al., 20194 for details) to assess climate change sensitivity,11 which consisted of eight yes-or-no questions based on whether the species’ habitat, ecology, physiology, or life cycle might be affected by changes in climate, a simplified version of existing vulnerability assessment protocols 12–14. Sensitivity results are summarized in Fig. 2, climate considerations are incorporated into the full dataset on climate change threat and management, and the full data for these species can be found in supplementary materials (Table S1 and Table S2).
The Hawaiian goose (Branta sandvicensis), the sole species in Delach et al. (2019) that was not described as having any of the eight climate sensitivities that we assessed, was downlisted to threatened in late 2019, and all new listings had at least one sensitivity; therefore 100% of endangered species were sensitive to one or more sensitivity factors. This indicates climate change is potentially a threat to all US endangered animals and underscores the importance of USFWS and NMFS addressing this threat in order to successfully conserve and recover species.
Our review of all new documents found that climate change was discussed much more frequently from 2019 on, across both the Trump and Biden administrations. The large number of documents published during these years meant that the number of species for which climate change was considered a threat increased from 64%4 to 85% of species (Fig. 1a) Fourteen species either lacked documents aside from the listing decision, or the recovery agencies explicitly determined that climate change was not a threat (“Not Applicable” in Fig. 1b). Of the remaining 444 species, 38% had climate related management actions described in one or more planning documents, over double the 18% in the previous analysis,3 with a further 8% in need of further study. Climate action planning has improved considerably in just four years but given that 100% of species have sensitivity characteristics that render them potentially vulnerable, the number of species for which climate-related actions are planned continues to lag far behind what is needed to conserve and recover these species in light of this threat.
Many of the 2019–2022 documents were generally substantially shorter and less detailed than previous iterations of these types. For instance, of single-species five-year reviews published 2009–2016, 14% were < 10 pages (n = 217); since 2017, 24% were (n = 324), and tended to focus on new information published since the prior review. Similarly, many recent recovery documents were outlines or amendments rather than full recovery plans. Consistent with the brevity of most of the documents, many of the actions planned were detailed in only one or a few sentences. For instance, the five-year review for the Atlantic salmon (Salmo salar) recommended development of a strategy that would “explicitly consider protection of climate-resilient spawning and rearing habitats in the face of climate change.” Similarly, in the “Recovery Outline for Hawaiian Multi-Island Species,” covering twelve endangered arthropods and one bird, the climate-related recovery objective was to "determine potential recovery areas with suitable projected climate conditions.” Thus, while the number of plans addressing climate change has increased since publication of Delach et al. (2019), the specificity and detail about those strategies has not. It is therefore unclear whether the actions planned by agencies will be appropriately designed, implemented, and monitored in a way that will maximize species resilience and continued recovery.
These results suggest that understanding of the threat posed by climate change has increased over time and is independent of presidential administration political affiliation. As the pace of document publication increased, fewer species have outdated documents: for instance, the number of species whose most recent document was published before 2007 has dropped from 46 (Delach et al. 2019) to 9. Even the most recently published documents, however, do not universally consider climate change as a threat (Fig. 1a). Furthermore, there remains a discrepancy between the number of species for which climate change is considered a threat and those where management plans reflect an action plan for it. The trend towards shorter and less detailed management plans is also concerning, as fewer specifics are given about all planned conservation actions, climate-related or otherwise. This continued shortfall in planning actions, despite the recognized level of threat, suggests that systemic issues like uncertainty about appropriate climate management responses, chronic funding shortfalls for species recovery and lack of agency capacity- which have been recognized by ESA experts as longstanding needs for improving ESA implementation and putting more species on the road to recovery15,16- are also impacting climate response.
As the effects of climate change continue to accelerate, well-informed and comprehensive planning measures will be essential to the conservation of our most imperiled species. Addressing the systematic issues within the USFWS and NMFS is imperative to ensuring effective recovery plans and conservation measures. Some such measures may include increased funding, ongoing climate-change educational courses, and trainings to equitably engage local communities so that agencies ensure they are creating comprehensive management plans and fulfilling the best available science mandate of the ESA. Increasing USFWS and NMFS capacity through greater funding and training as well as mindfully and intentionally incorporating local communities’ input into management plans may help bolster the efficacy of these strategies under an increasingly extreme climate.