On Sept. 26, the most powerful tool for protecting animals and plants in the U.S. will lose some teeth. That’s when new rules will alter the Endangered Species Act – credited with rescuing iconic creatures, such as the bald eagle and the Florida manatee – to make it easier to remove species from the list, and weaken protections for species classified one step below endangered, among other changes. Proponents of the changes say they will bring greater transparency to the rules, and ease the regulatory burden on mining companies, oil and gas drilling outfits and others in areas where protected species live. Opponents say the changes will make it significantly harder for endangered species to recover.

A bald eagle perched on a tree branch in Kachemak Bay, Alaska. The Endangered Species Act helped bring the bald eagle back from the brink of extinction in the continental U.S. (Image credit: pxhere.com)

A number of environmental groups have filed a lawsuit to stop the changes, and several state attorneys general have done the same.

Stanford biologist Elizabeth Hadly and legal expert Michael Wara discuss likely impacts of the new rules and legal options below.


Why are these revisions to the Endangered Species Act (ESA) a priority for the Trump administration?

Wara: The ESA is viewed by many rural western landowners as a significant limitation on the use of their land. Their view is that the law unfairly levies costs on them or even expropriated their property. This revision of the ESA has long been a priority for conservative Republicans in rural states – a core component of Trump’s base.


What are the major strengths and weaknesses of the act, as it was originally written?

Hadly: The Endangered Species Act, passed by bipartisan votes in both the Senate and House and put into place by Republican President Richard Nixon in 1973, is a powerful and important piece of legislation. It has balanced the needs of species against the local, regional, national and international drivers of development and resource extraction. It is imperfect in that it puts the onus of protection onto individual species, not the ecosystems on which they depend. However, the ESA has served to educate the public, and scientists as well, about how ecosystems work and how they can come unraveled by removal of particular species and why. Over the past 46 years, the ESA has protected more than 200 species, yet many more need its protection now, more than ever.


How will the changes affect the way that regulators make decisions about listings, delisting, reclassifications and critical habitat designations?

Wara: The final rules enact a diverse set of changes to all of the activities required by the endangered species act. In general, the rules require tighter causal links between protections and threats to the listed species. This may mean that it is harder to protect species that are imperiled by our changing climate – although precisely how this impact is incorporated into decisions remains to be seen. In addition, the changes seek to accelerate the consultation process that other federal agencies must engage in before they take actions that may jeopardize a listed species.

Hadly: The most critical changes are that regulators will now be able to weigh the economic costs of protecting species, and that climate change will be a less important consideration. The latter will make it harder to list species that increasingly face anthropogenic threats such as degraded habitats and barriers to migration just as a changing climate forces them to seek new habitats.


The revision will make it more difficult for regulators to factor in the effects of climate change on wildlife. What animals stand to lose the most from this change (e.g., birds whose migration patterns are shifting because of temperature changes)?

Hadly: Particularly salient examples include the northward movements of species such as the grizzly bear, which is moving into Arctic environments occupied by the polar bears, who cannot move further north. Or the forest species now threatened by the eradication of vast swaths of our coniferous forests in the Sierras and Rocky Mountains because of the increased reproduction and survival of pine and bark beetles made possible by warmer winters.


The revision allows regulators to factor economic assessments into species protection decisions. Is there a precedent for that in environmental regulations? What is the likely impact?

Wara: Regulations have long forbid consideration of cost, consistent with both the statute and its interpretation by the courts. Now, the implementing agencies will “compile” and “present” costs of a listing, but will not use these as a factor in evaluating whether to list. Courts will likely scrutinize this approach closely. The reality is that economic impacts already enter into many listing decisions, just not explicitly. A recent example is the decision not to list the Sage Grouse because of its impact on western oil and gas extraction. It remains to be seen how this change will modify the practice (as opposed to the theory) of listing under the ESA.


What legal and legislative avenues might opponents of the changes pursue?

Wara: The most promising avenue for challenging the regulatory changes will be the courts. In order to prevail, the Trump administration will have to provide a reasoned basis for the changes and show that they are consistent with the underlying law. Particularly on costs, this will require a court to overrule longstanding Supreme Court precedent forbidding consideration of costs under the Endangered Species Act.


Hadly is the Paul S. and Billie Achilles Professor in Environmental Biology in Stanford’s School of Humanities and Sciences; a member of Bio-X; and a senior fellow in the Stanford Woods Institute for the Environment. Wara is a senior research scholar at Woods.

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Media Contacts

Elizabeth Hadly, Biology: (650) 245-1775, hadly@stanford.edu

Michael Wara, Stanford Woods Institute for the Environment: (415) 250-9730, michael.wara@stanford.edu

Rob Jordan, Stanford Woods Institute for the Environment: (650) 721-1881, rjordan@stanford.edu