A More Cautious Approach to Wind Power
Scientific experts, as well as a large portion of the general public agree that our reliance on fossil fuels is not sustainable given the rapidly warming climate of our planet. To prevent a mass extinction, many governments as well as private actors are turning to renewable energy sources, such as solar panels, hydropower, and wind power. In 2019, the American Wind Energy Association reported that wind power had become the #1 renewable energy source in the United States.[1] While this rapid expansion has undeniable benefits to the environment, new technologies pose new risks and ecological repercussions many of which we are only beginning to understand.
For example, migratory tree bats (genera Lasiurus Lasionycteris) appear to be more vulnerable to wind turbine collisions than previously predicted.[2] Every year thousands of bats succumb to death associated with wind turbines in the United States and across North America.[3] While the reasons for this remains largely unknown, research suggests bats may not echolocate during migration which could explain higher rates of mortality during this time.[4]
Bats play an invaluable role in maintaining healthy ecosystems, maintaining insect populations, spreading seeds, and pollinating plants. It is estimated that the amount of insects bats consume adds up to $3.7 billion worth of pest control each year.[5] Additionally, bats are important pollinators and seed spreaders.[6] Thus, reductions in bat populations will have devastating consequences for humans as well as many other plant and animal species. Considering the essential role bats play in the ecosystem and the voluminous threats already facing this genera, new projects that may affect them must be approached with great caution.
Bats are among the most endangered animals in the world because of habitat loss due to human development.[7] Currently, the United States federal government lists eleven species of bats as endangered, and two species as threatened.[8] The IUCN currently lists the Eastern Pipistrelle (Perimyotis subflavus) as vulnerable partially due to development of wind turbines in North America.[9]
The National Environmental Policy Act (NEPA) “requires federal agencies…to consider and report on the environmental effect of their proposed actions”[10] with the goal of ensuring that detailed information on the environmental impacts of proposed actions are considered by the agency.[11] By requiring close attention by the agency and the public to the potential effects of the action, NEPA aims to avert regrettable decisions based on incomplete information and irreparable damage to the environment.[12] With that in mind, a federal agency must prepare an environmental impact statement (EIS) for major federal actions that may significantly affect the quality of the human environment.[13]
In conjunction with NEPA’s procedural requirements, the Endangered Species Act (ESA) aims to defend endangered and threatened wildlife, plants, and their habitats by requiring federal agencies to ensure that actions it authorizes are not likely to “jeopardize the continued existence of any endangered species…or result in the destruction or adverse modification of habitat of such species.”[14] Under this mandate, the designated agency is responsible for reviewing proposed actions and potential alternatives in order to mitigate habitat loss and unnecessary harm to a species as a whole.[15] [16]
Currently, there are several viable options for reducing bat deaths:
Twelve studies show that increasing the wind speed at which turbines become operational can be beneficial to bat species.[17]
Six studies show that preventing turbine blades from turning at a low speed can reduce bat fatalities.[18]
Two studies show that automatically reducing turbine blade rotation when bat activity is predicted to be high can result in fewer bat fatalities.[19]
Determining additional ways to reduce bat fatalities due to wind power will not only require additional research, but a change in our current research methods to support legislative reform and judicial decision making. Environmental Impact Assessments (EIAs) are used around the world to predict the overall positive and negative effects of windfarm developments. However, EIAs do not accurately predict the risks wind turbines pose to bats.[20] For more effective policy making, post-construction surveys are necessary.[21]
As plans to construct large-scale wind farms in the United States increase, the need to understand the impact of these structures is becoming evermore urgent. We are eager to see the steps the legal and regulatory systems will take to protect bat species across the U.S.
REFERENCES
[1] https://www.powermag.com/wp-content/uploads/2020/04/awea_wpa_executivesummary2019.pdf
[2] Wind Energy and Wildlife Resource Management in Iowa: Avoiding Potential Conflicts- Iowa white paper
[4] Baerwald, E.F., Barclay, R.M.R., 2009. Geographic variation in activity and fatality of migratory bats at wind energy facilities. Journal of Mammalogy 90, 1341-1349.
[5] Benefits of Bats - Bats (U.S. National Park Service) (nps.gov)
[6] Id.
[7] IUCN SSC Bat Specialist Group - Home (iucnbsg.org)
[9] Eastern Pipistrelle; Solari, S. 2018. Perimyotis subflavus. The IUCN Red List of Threatened Species 2018: e.T17366A22123514. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T17366A22123514.en. Downloaded on 22 August 2021.
[10] WildEarth Guardians v. Jewell, 738 F.3d 298, 302, 407 U.S. App. D.C. 309 (D.C. Cir. 2013)
[11] Baltimore Gas & Elec. Co. v. NRDC, 462 U.S. 87, 97, 103 S.Ct. 2246 (1983)
[12] Klamath Siskiyou Wildlands Ctr. v. Boody, 468 F.3d 549 (9th Cir. 2006).
[13] 42 U.S.C. § 4332(2)(c)
[14] 16 U.S.C. § 1536(a)(2)- The Endangered Species Act
[15] Union Neighbors United, Inc. v. Jewell, 31 F.3d 564, 581 (D.C.Cir. 2016)
[16] 42 U.S.C. § 4322(c)
[17] Berthinussen A., Richardson O.C., Altringham J.D. (2021) Bat Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synposes. University of Cambrige, Cambridge, UK.
[18] Berthinussen A., Richardson O.C., Altringham J.D. (2021) Bat Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synposes. University of Cambrige, Cambridge, UK.
[19] Berthinussen A., Richardson O.C., Altringham J.D. (2021) Bat Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synposes. University of Cambrige, Cambridge, UK.
[20] Ecological impact assessments fail to reduce risk of bat casualties at wind farms
[21] Id.
