A George W. Bush-era policy prevented federal agencies from considering the harmful effect of greenhouse gas emissions on endangered polar bears, but new peer-reviewed research illustrates a direct link.
The 2008 policy created a loophole in Section 7 of the Endangered Species Act, which is designed to protect endangered species from federal actions, such as issuing permits for greenhouse-gas emitting projects. But as Earth continues to heat way beyond natural variability, Arctic sea ice expanse on which polar bears depend continues to decline. The new research connects the dots between greenhouse gas emissions and the amount of ice melt, and the subsequent inability of polar bears to find food.
The study, published Aug. 31 in Science magazine, focused on polar bears because the researchers, Steven C. Amstrup and Cecilia M. Bitz, had the data “to make the quantitative link between emissions, sea ice, and polar bear demographics,” they wrote. Also, it was the ESA listing of polar bears that prompted the Bush Administration to create the loophole, undermining efforts to protect polar bears in a human-induced overheating world.
How this research could benefit endangered salmon
The ramifications of this new research “go far beyond polar bears and sea ice,” the researchers wrote. “It seems reasonable that similar regression links could be established between emissions, water temperature change, and impacts on both freshwater and marine species of plants and animals.”
Multiple salmon species in the Pacific Northwest are listed as endangered, and warming river, stream, and reservoir temperatures are known threats to their survival. Salmon begin to suffer harmful effects when water temperatures exceed 68 degrees Fahrenheit, and the Pacific Northwest is increasingly susceptible to extreme heat and drought events that warm inland waters. Water temperatures exceeded 70°F in reservoirs behind dams on the lower Snake River and the Columbia River, according to a recent Save Our Wild Salmon Hot Water Report.
Dams both large and small restrict the flow of rivers, which, on hot summer days, allow the slower-flowing rivers and reservoirs created by the dams to heat up faster and to hotter temperatures than before the flows were restricted. Water temperatures in the intensively dammed lower Snake and Columbia Rivers have exceeded lethal levels for salmon survival for as long as two months each summer over the last 10 years, according to the SOWS Hot Water Report.
Dam removal critical to restoring salmon runs
A 2022 National Oceanographic and Atmospheric Administration National Marine Fisheries Service report on Columbia River basin fish habitat restoration cites numerous examples of dam removal as a critical factor in restoring endangered salmon runs, as well as other endangered species: “The science robustly supports…habitat restoration, dam removal (breaching), and ecosystem-based management, and overwhelmingly supports acting, and acting now.”
The Yakima Nation called for the removal of three lower Columbia River dams in 2019, blaming them for decimating their “fisheries, traditional foods, and cultural sites.” And last year the American Fisheries Society called for the removal of four dams on the lower Snake River because they “significantly reduce access to the cold-water, high-quality spawning and nursery habitat that are essential for fish sustainability.”
Removing Bush-era loophole beneficial to all
The new research by Amstrup and Bitz confirming the link between rising greenhouse gas emissions, dwindling Arctic sea ice, and the negative implications for the survival of polar bears now is the “best available science” — a key tenet of the Endangered Species Act that must be met when assessing a species in decline. As they concluded in their paper:
…the Department of the Interior now has the scientific justification and duty to rescind [the Bush-era policy] — allowing the U.S. Fish and Wildlife Service to include anthropogenic GHG emissions in Section 7 consultations and meet its responsibility under the ESA to protect polar bears as well as other species imperiled by climate warming.
Beyond polar bears and sea ice, Amstrup and Bitz also reference President Biden’s mandate for a “Government-wide approach that reduces climate pollution in every sector of the economy.” And the fact that Arctic sea ice plays a critical role in moderating global heating by reflecting the Sun’s energy back into space is yet another reason to rescind the loophole: “…protecting polar bears from anthropogenic climate warming also will benefit the rest of life on Earth — including humans.”