Skip to content

About PERC

All Areas of Focus

All Research

The New Endangered Species Act Rules, Explained

  • Jonathan Wood
  • In August, the Departments of the Interior and Commerce announced new rules concerning implementation of the Endangered Species Act. Much of the media coverage was over-the-top, questioning whether the new rules “gutted” the act or were a giveaway to big oil, even asking: “Why does Trump hate polar bears and kids?” This isn’t unusual; almost every proposed change under the law has evoked such responses, even when proposed under presidents generally viewed favorably by environmentalists.

    The new rules do a wide variety of things, including codifying long-standing policies, making minor technical tweaks, and implementing more significant, substantive changes to how the law is implemented. So what do these new rules really mean for endangered and threatened species?

    Economic Impacts in Listing Decisions

    The Endangered Species Act requires Interior and Commerce to determine whether or not a species warrants an endangered or threatened listing based solely on the science, without consideration of economic impacts. Previously, agency regulations also required such decisions to be made “without reference to possible economic or other impacts of such determination.” One of the new rules deletes this requirement.

    This rule change does not allow economic impacts to affect whether a species is listed as endangered or threatened. Indeed, the rule explicitly “acknowledge[s] that the statute and its legislative history are clear that listing determinations must be made solely on the basis of the best scientific and commercial data available” according to five statutory factors. Thus, the rule gives the agency no authority to decline to list a species based on the economic impacts of such a decision. If the agency attempted to do so, it would violate the statute and the rule.

    Although this change has no effect on listings, it may have political significance. In fact, the agencies justify the rule on transparency grounds, explaining that they intend to report these economic impacts to better inform the public. If the costs are extraordinarily high, some fear this may create political momentum for Congress to amend the Endangered Species Act.

    But this risk seems remote. Economic impacts are considered and reported under several other parts of the act. For instance, critical habitat can only be designated “after taking into consideration the economic impact.” The economic impacts reported under this provision can be exceedingly high. Critical habitat for the green sturgeon, for instance, was estimated to cost up to $600 million per year. Many other species have estimated impacts exceeding $100 million, and the cumulative impacts are well into the billions. Yet protecting species remains extremely popular.

    Consideration of Climate Change Impacts

    The Endangered Species Act distinguishes between “endangered” species (those at risk of extinction today) and “threatened species” (those likely to become endangered “within the foreseeable future”). The new rules define the “foreseeable future” as “extend[ing] only so far into the future as the Services can reasonably determine that both the future threats and the species’ responses to those threats are likely.”

    Some have suggested this rule will make it harder for the agencies to list species threatened by climate change; however, the rule merely codifies the policy the agencies have followed since 2009. Since that time, numerous species have been designated based on climate change impacts. In 2012, for instance, the Department of Commerce designated several populations of bearded seal as threatened by climate change and the loss of sea ice, relying on modeling from the Intergovernmental Panel on Climate Change. In doing so, the agency explicitly followed the 2009 policy.

    To be sure, others have argued that climate science is too speculative to affect listing decisions. And they will likely continue to do so. But the new rule doesn’t make it harder for the agencies to rely on climate science. Instead, it merely makes public and binding the policy that has governed listing decisions during the George W. Bush, Obama, and Trump administrations.

    Threatened Species

    One of the new rules restores the Endangered Species Act’s distinction between the regulation of endangered and threatened species. When Congress enacted the law in 1973, it reserved the “take” prohibition—which forbids activities that affect any member of a species or its habitat—for endangered species. The prohibition could be extended to threatened species too, but only if the agencies deemed it “necessarily and advisable” for the conservation of the species.

    In 1975, the Interior Department issued a blanket rule that extended this prohibition to all threatened species, unless it adopted a special rule relaxing the prohibition for a particular species. In essence, the blanket rule provided no meaningful distinction between regulations for species that are listed as threatened or endangered.

    One of the new rules issued in August repeals the blanket rule—thus restoring Congress’ original distinction between threatened and endangered species. This move aligns Interior’s practice with that of the Commerce Department, which has never had a blanket rule. (The Commerce Department manages marine species, like whales and most fish.) This new rule only applies prospectively. So the blanket rule continues to cover species previously listed as threatened, meaning no species lose any protection because of the change.

    This change has been described as “weakening” protections for threatened species. But that doesn’t necessarily mean that species will fare worse under the new rule than they did under the old one. In the PERC Policy Report The Road to Recovery, I’ve argued that restoring regulatory distinctions between endangered and threatened species will better align the incentives of landowners with the interests of rare species. Under the new rule, burdens imposed on landowners will increase if species decline and relax as they recover, giving landowners a significant stake in a species’ status.

    In fact, the rule change formalizes a shift begun under the Obama administration. According to a Defenders of Wildlife report published in 2017, the Obama administration’s Interior Department relied less frequently on the blanket rule than nearly any other administration, opting instead to relax “take” prohibitions using the same type of “species-specific” rules that will now be more common under the new rules for threatened species. Indeed, the new rule adopts the same policy the Commerce Department has followed for decades, with no evidence that it has undermined the protection of species under its authority.

    Of course, the way agencies implement this change going forward matters a great deal. But the new rule holds significant promise for boosting the rate at which we recover endangered species, which is currently under 3 percent.

    Critical Habitat

    The Endangered Species Act directs that land essential to the conservation of endangered and threatened species be designated as critical habitat. This can include lands occupied by the species or unoccupied lands. The effect on property owners of such designations may include additional permitting or mitigation requirements for any use of designated land that requires a federal permit.

    The new rules require all occupied areas to be designated as critical habitat before unoccupied areas can be considered. This restores a rule that was in place until 2016. It likely means that unoccupied areas will continue to be a small percentage of designated critical habitat. Since 2007, for instance, roughly 97 percent of critical habitat was occupied at the time of listing.

    Although unoccupied areas are rarely designated, they are an outsized source of controversy. In 2011, Interior designated 1,500 acres as critical habitat for the dusky gopher frog on private lands in Louisiana, despite the fact that none had been seen there in 50 years and the land would require extensive restoration work to become suitable for the species once again. Despite the lack of benefit to the species, the designation could have cost the landowner up to $34 million in lost development value. A challenge to that designation ultimately reached the U.S. Supreme Court last fall, which held in a unanimous decision that only habitable land could be designated as critical habitat.

    The new rules aim to reduce the number of such conflicts and address (in part) the effects of the Supreme Court’s decision. They require any unoccupied lands designated as critical habitat to “contain one or more of the physical or biological features essential to the species’ conservation” and a “reasonable certainty” that the land “will contribute to the conservation of the species.”

    These changes will likely discourage marginally the designation of unoccupied land. But given the limited historical reliance on such lands, the need to conform agency practice to the Supreme Court’s decision, and the fact that conflicts over these lands benefit neither property owners nor species, the effect of the change will be modest.

    The wood stork was downlisted from endangered to threatened.

    Delisting Species

    Finally, the new rules also provide that “[t]he standard for a decision to delist a species is the same as the standard for a decision not to list it in the first instance.” In other words, there is no higher standard for delisting species than applies to the initial decision to list it. This is consistent with the Endangered Species Act’s text, which addresses both listing and delisting decisions under the same provision and with the same five-factor test.

    Some have argued that the bar for delisting a species should be much higher than the bar to list a species, reflecting a more cautious approach. And some courts seem to have erected such barriers. For instance, asserting that the standard should be higher “when a species is already listed,” a federal court recently struck down the delisting of the Yellowstone grizzly bear, despite extensive, bipartisan recovery efforts that enabled the species to exceed its recovery goal (and likely its ecosystem’s carrying capacity).

    But a heavy thumb on the scale against delisting may not be in the long-term interests of endangered species. One of the primary incentives for recovery efforts is the promise that, if the efforts succeed, the species will be delisted, and federal regulations will be lifted. Making delisting too difficult may have the unfortunate consequence of discouraging efforts to recover species.

    Interagency Cooperation

    The Endangered Species Act also requires agencies to consult with the Interior and Commerce Departments if the activities they undertake, approve, or fund may affect listed species. If any activity will jeopardize a species’ survival or adversely modify its habitat, it is prohibited. But determining whether these standards are met can be a drawn out and expensive process. One of the new rules adopts several changes to this interagency process, although most are of a technical variety.

    These changes include focusing on the effects that are most certain to occur, establishing a baseline against which to compare those effects, clarifying the information required, setting deadlines for reviews, and establishing the standards that apply to these reviews. Of all the rules, this is the one that depends most on how agencies implement it (which is perhaps unsurprising for a largely procedural rule). To fully diagnose the rule, we’ll have to wait and see how it works in practice.

    But it’s important to bear in mind how infrequently these interagency reviews result in findings that projects will jeopardize a species or adversely modify its habitat. According to a previous Defenders of Wildlife study, none of the more than 100,000 projects that underwent this review from 2008 to 2015 led to a jeopardy or adverse-modification determination. This is likely because agencies have gotten pretty good over the last 45-plus years in adjusting projects to avoid or mitigate impacts to endangered species prior to submitting them for review, in the hopes of streamlining the review process. That knowledge won’t go away.


    The Endangered Species Act is a popular and important law, so it’s no surprise that changes to its implementation evoke strong feelings and rhetoric. Ultimately, details matter more than rhetoric. If we’re serious about protecting endangered species, it is imperative that we find ways to preserve what the statute does well—prevent extinctions—while improving it as a tool to recover species.

    Written By
    • Jonathan Wood
      • Vice President of Law & Policy

      Jonathan Wood is vice president of law and policy at PERC, leading PERC’s Conservation Law and Policy Center.

    Related Content