To help meet our growing energy needs, in recent years we have increasingly turned to wind power. The U.S. Energy Information Administration estimates that in 2014, 4.4 percent of the electricity we generated came from wind.
However, the wind industry is set to expand exponentially from the current 60,000 megawatts of capacity to 300,000 by 2030. Some estimates indicate that this growth will avoid putting 100 million tons of carbon dioxide emissions into the atmosphere, a reduction critical to mitigating the effects of rapid climate change.
This good news, however, comes at a price. A study just published in the June 2015 Journal of Applied Ecology demonstrated that half of the harbor seals being observed near a wind farm that was under construction were exposed to pile-driving noise levels that exceeded auditory damage thresholds for pinnipeds.
In a battle between good vs. good—clean energy vs. healthy populations of wildlife—how do we choose?
Seal hearing loss
The damage that wind farms can do to bird populations has long been known. In 2013, an article published in the Journal of Raptor Research reported that from 1997 to 2012, turbines on wind farms in 10 states killed at least 85 bald and golden eagles—a number researchers say is most likely an underestimate because of the lack of rigorous monitoring and mortality reporting. Conservationists worry that even a small number of golden eagle fatalities could be a significant problem, since their population numbers are not well known.
In the brand-new, June 2015 study, researchers from Scotland’s University of St. Andrews glued tracking tags to the backs of 24 harbor seals at haul-out sites near a wind farm that was under construction, located about five miles off the southeast coast of England.
From January to mid-May 2012, while workers installed 31 steel pilings for the turbine foundations, the researchers tracked the seals’ movements. The tags provided each seal’s location every 15 minutes and the depths of their dives. They then combined that data with the location, time and force of nearly 78,000, individual pile-driving blows, which produce a pulse of underwater sound as loud as 250 decibels every one to two seconds.
The study’s results showed that all of the seals were exposed to noise levels thought sufficient to cause temporary hearing impairment. Twelve of the 24 seals were subject to noise levels above the threshold for permanent hearing damage at least once and, in some cases, up to nine times during the study period. Since underwater hearing in seals likely plays a big role in helping them avoid predators, find and compete for mates, and follow the movements of prey species, such exposure is meaningful in relation to their chances for survival.
Clean energy fixes
The modern era of wind energy began in California in the 1980s. Due to the high cost of fossil fuels, a moratorium on nuclear power and an awareness about environmental concerns, the state provided tax incentives to promote wind power. Additional federal tax incentives motivated small companies and entrepreneurs in the state to install 15,000, medium-size turbines, providing enough power to meet the residential needs of a city the size of San Francisco. After the tax credits expired in 1986, wind power continued to grow, although more slowly.
Today, however, several thousand new wind turbines are proposed for installation off the coast of Europe—many of them in seal habitat. Luckily, as the wind industry matures, better siting and technological improvements should contribute to reducing impacts on wildlife. Some potential solutions put forward are to build wind farms only near cities and to use existing transmission lines and roads; to locate them only in areas with little wildlife habitat value, such as abandoned agriculture areas, already degraded lands or former industrial sites; and to incorporate measures that protect or restore similar habitat and ecosystems to compensate for any unavoidable wildlife ramifications.
Technological developments to help offset the impacts of wind installations include radar systems that can detect approaching birds—causing turbines to automatically turn off—and fiber shrouds that would allow birds and bats to see the entire rotor display, protecting them from the spinning blades.
Environmentalists vs. environmentalists
If this were merely a case of environmentalists against big energy, things would be simpler. Whether it’s eagles dying from wind farms on land or seals losing their hearing from wind turbines at sea, even clean energy has environmental impacts. As some have expressed it, “it makes no difference to a sage grouse if its habitat is destroyed by an oil derrick or a wind turbine.”
With only 50 parts per million of greenhouse gases now standing between us and disaster, fast-tracking clean energy makes sense. But whether we can simultaneously achieve clean energy goals and preserve species remains to be seen.
Do you think that rapid climate change is a bigger threat than species loss? Can we deal with one and safeguard the other?
Here’s to finding your true places and natural habitats,