The ozone layer has been on track to recover thanks to the Montreal Protocol—but a loophole may be holding it back. Chemicals still permitted for industrial use are leaking into the atmosphere at higher rates than expected. Scientists now estimate this could delay ozone recovery by up to seven years. Closing this gap could speed up healing and reduce harmful UV exposure worldwide.

Scientists searching for air pollution clues stumbled onto something unexpected: toxic MCCPs drifting through the air for the first time in the Western Hemisphere. The likely source—fertilizer made from sewage sludge—points to a hidden route for contamination.

Plastic pollution is not just in oceans and soil. Scientists have now found enormous amounts of microscopic plastic floating through urban air, far exceeding earlier estimates. Road dust and rainfall play a major role in moving these particles through the atmosphere. The findings suggest the air may be one of the most important pathways for plastic pollution.

CO2 can stimulate plant growth, but only when enough nitrogen is available—and that key ingredient has been seriously miscalculated. A new study finds that natural nitrogen fixation has been overestimated by about 50 percent in major climate models. This means the climate-cooling benefits of plant growth under high CO2 are smaller than expected. The result: a reduced buffer against climate change and more uncertainty in future projections.

This year’s ozone hole over Antarctica ranked among the smallest since the early 1990s, reflecting steady progress from decades of global action under the Montreal Protocol. Declining chlorine levels and warmer stratospheric temperatures helped limit ozone destruction. Scientists say the layer remains on track to recover later this century.