Climate Adaptation for Non-Humans: The Role of Assisted Migration

Bull_Trout_RuhlBy Christine Zaleski—April 22 at 5:02 p.m.

On January 30, 2015, President Obama again demonstrated his willingness to tackle climate change issues using his executive authority, signing an Executive Order requiring new federal buildings constructed in floodplains to be built at higher elevations. This action is one of many that governments around the world have taken to adapt to the sea-level rise caused by climate change. While humans are adapting to sea-level rise by changing the elevation at which they live, many species lack such an option because natural and man-made obstacles prevent them from migrating to upland habitat. In the current issue of the Harvard Environmental Law Review, Jaclyn Lopez’s “Biodiversity on the Brink: the Role of ‘Assisted Migration’ in Managing Endangered Species Threatened with Rising Seas,” proposes several policy options to help species threatened with coastal inundation to migrate to safe habitats.

Squeezed between rising sea levels and human development, some endangered species are at risk of extinction, not for lack of available habitat, but for lack of accessible habitat. Migration corridors between existing at-risk habitat and available habitat elsewhere are scarce. Proponents of “assisted migration” would address this problem by helping populations of endangered and threatened species move to suitable habitat. Assisted migration can be accomplished either through active or passive assistance: humans can physically move plants and animals from threatened habitats to secure habitats, or humans can protect corridors of suitable habitat that permit the species themselves to migrate. Lopez recommends that the U.S. Fish & Wildlife Service (“FWS”) use existing authority under the Endangered Species Act to incorporate active assisted migration into species recovery plans and to integrate projections about sea-level rise into critical habitat designations. The FWS could and should designate some currently unoccupied habitat as “critical” in order to preserve corridors and alternative habitat for endangered species facing “coastal squeeze.” Lopez discusses the implications of her recommendations for four federally protected species from differing taxa, habitat types, and natural histories—the Florida panther, loggerhead sea turtle, Key tree-cactus, and Lower Keys marsh rabbit—to demonstrate the critical need for action to protect endangered and threatened species facing coastal squeeze.

To date, actions such as these, occurring wholly within the executive branch, have been the primary federal drivers of climate change mitigation and adaptation. The Executive Order President Obama signed in January amended Executive Order 11,988, signed by President Carter in 1977. The long legacy of Executive Order 11,988 is a testament to the durability of some executive actions. However, as President Obama’s actions demonstrate, executive orders and changes to agency policy are vulnerable to changes in the administration.

On January 30, 2015, the same day that President Obama signed the amendments to Executive Order 11,988, the New York Times reported that 74% of Americans believe that the federal government should be doing a “substantial amount” to combat climate change.[1] Perhaps this signals that the tide is turning and climate change policy may find support outside the executive branch, as it has among the American public. If that is true, these executive actions can become stepping-stones to less fragile, more comprehensive legislation.

[1] Coral Davenport & Marjorie Connelly, Most Republicans Say They Back Climate Change Action, Poll Finds, N.Y. Times, (Jan. 30, 2015).