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.

Long-term inhalation of toxic air appears to dull the protective power of regular workouts, according to a massive global study spanning more than a decade and over a million adults. While exercise still helps people live longer, its benefits shrink dramatically in regions with heavy fine particle pollution—especially above key PM2.5 thresholds common in many parts of the world. The researchers emphasize that outdoor activity shouldn’t stop, but better air quality could unlock far greater health gains.

Wildfires are no longer a seasonal nuisance but a deadly, nationwide health crisis. Fueled by climate change, smoke is spreading farther and lingering longer, with new research warning of tens of thousands of additional deaths annually by mid-century. The health costs alone could surpass all other climate damages combined, revealing wildfire smoke as one of the most underestimated threats of our warming world.