Supreme Court Chief Justice John G. Roberts Jr. denied a request for a stay or injunction of the U.S. Environmental Protection Agency’s Mercury and Air Toxic Standards (MATS) rule—a rule that 20 states have claimed is “unlawful and beyond EPA’s statutory authority.” The ruling means MATS, which requires coal-burning power plants to install technologies to reduce emissions of toxic pollutants, remains in effect while the EPA continues its study of compliance costs.
The stay denial, issued solely by Chief Justice Roberts and without comment, follows a June Supreme Court decision in which five justices found that the EPA should have considered compliance costs when determining whether it was “appropriate and necessary” to regulate mercury emissions from the power sector. The June ruling did not strike down the regulation; rather, it required the EPA to take costs into consideration.
In a supplemental finding proposed in November, the EPA indicated that the costs of implementing MATS were reasonable. The EPA is expected to finalize its cost accounting, which seeks to address court concerns, in April.
“These practical and achievable standards cut harmful pollution from power plants, saving thousands of lives each year and preventing heart and asthma attacks,” said Melissa Harrison, EPA spokeswoman.
Melting of Greenland’s Ice Sheet Accelerating with Loss of Reflectivity
A study in European Geosciences Union journal The Cryosphere finds that the reflectivity, or “albedo,” of Greenland’s ice sheet could decrease by as much as 10 percent by the end of the century, potentially leading to significant sea-level rise (subscription). The study links the diminishing capacity of Greenland’s ice sheet to reflect solar radiation—so-called “darkening”—to positive feedback loops that quicken ice melt, allowing it to feed on itself.
Scientists have been aware of the feedback loops, lead author Marco Tedesco, a professor at Columbia University’s Lamont-Doherty Earth Observatory, told the Christian Science Monitor. “What’s new,” he said, “is the acceleration of the darkening, which started in 1996.”
The research used satellite photos dating back to 1981 plus a model to examine the impact of increases of both impurities in the ice, often visible to the human eye, and the size of grains in the snowpack, which is often invisible to the human eye and which makes snow “‘darker’—not dirtier, but more absorbent of energy from the sun,” said Tedesco. As snowpack melts and refreezes, meltwater binds grains together. The larger the grains, the less reflective the surface of the ice sheet and the faster the melting, which keeps speeding up as the remaining impurities become concentrated at the surface.
The study attributes the acceleration of darkening in 1996 to a change in atmospheric circulation. The North Atlantic Oscillation, a natural weather cycle, went into a phase that favored incoming solar radiation and warm, moist air from the south. Although those conditions shifted in 2013 to favor less melting, the sensitivity of the ice sheet to atmospheric air temperatures had already increased, and in 2015, melting spiked again, affecting more than half of the Greenland ice sheet.
The study rejected one prominent theory of Greenland’s darkening—namely, that worsening wildfires are releasing soot that is increasingly falling on Greenland. It finds “no statistically significant increase” in black carbon from fires in northern regions and an increase that is likely too small to matter from wildfires in temperate North America.
“Overall, what matters, it is the total amount of solar energy that the surface absorbs,” said Tedesco. “This is the real driver of melting.”
U.S. Makes First Green Climate Fund Payment
The United States has made the first payment to the United Nation’s Green Climate Fund (GCF). The $500 million payment is part of a broader $3 billion pledge to the GCF, which helps poor countries fight climate change and adopt clean energy technologies.
“With this announcement, which comes less than three months after the historic Paris climate agreement, the United States continues to demonstrate leadership in the international climate arena,” a State Department official told The Hill. “This grant is the first step toward meeting the president’s commitment of $3 billion to the GCF and shows that the United States stands squarely behind our international climate commitments.”
The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University’s Nicholas Institute for Environmental Policy Solutions.