Although ozone pollution is dropping across many parts of the United States, western Europe and Japan, many people living in those countries still experience numerous days every year in which levels of the lung irritant exceed health-based standards.

Global ozone has been declining since the 1970s owing to certain man-made chemicals. Since these were banned, parts of the layer have been recovering, particularly at the poles.

Although ozone pollution is dropping across many parts of the United States, western Europe and Japan, many people living in those countries still experience more than a dozen days every year in which levels of the lung irritant exceed health-based standards.

Greenland’s vast ice sheet has long been home to Project Iceworm, an abandoned Cold War-era U.S. Army initiative designed to deploy ballistic missiles with nuclear warheads against the Soviet Union. When the project was shuttered in 1967, military planners expected that any materials left on site would be safely frozen in ice and snow in perpetuity.

Some of the smallest creatures on the planet — zooplankton — make the most widespread vertical migration of biomass on Earth. Billions of these animals move deeper into the ocean and away from the light during the day to avoid predators, and migrate up again in the dark of night to feed.

A previously unrecognized source of nitrogen oxide is contributing up to about 40 percent of the NOx emissions in California, according to a study led by the University of California, Davis. The study traces the emissions to fertilized soils in the Central Valley region.

The 2018 Environmental Performance Index (EPI) finds that air quality is the leading environmental threat to public health. Now in its twentieth year, the biennial report is produced by researchers at Yale and Columbia Universities in collaboration with the World Economic Forum. The tenth EPI report ranks 180 countries on 24 performance indicators across 10 issue categories covering environmental health and ecosystem vitality. Switzerland leads the world in sustainability, followed by France, Denmark, Malta, and Sweden.

Switzerland’s top ranking reflects strong performance across most issues, especially air quality and climate protection. In general, high scorers exhibit long-standing commitments to protecting public health, preserving natural resources, and decoupling greenhouse gas (GHG) emissions from economic activity.

For coral reefs, the threat of climate change and bleaching are bad enough. An international research group led by Cornell University has found that plastic trash – ubiquitous throughout the world’s oceans – intensifies disease for coral, adding to reef peril, according to a new study in the journal Science, Jan. 26.

Man-made phosphorus pollution is reaching dangerously high levels in freshwater basins around the world, according to new research.

Mercury is a widespread environmental toxicant and pollutant that travels up the food chain onto people's dinner plates. Although a global issue, mercury regulations vary worldwide. Depending on where one lives in relation to mercury emissions, regional remediation makes minimal impacts for local fish consumption advisories. This is particularly true in a sensitive landscape like Michigan's Upper Peninsula, where nearly 80 percent of inland lakes are impaired.