On top of rising greenhouse gas emissions, aerosol pollution which would normally cool Earth has fallen.

New research illustrates why popping bubbles fire some contaminants into the air, while allowing others to sink harmlessly.

Thanks to humans, the concentration of planet-warming carbon dioxide in the atmosphere is now 50% higher than before the industrial era. These gases are raising Earth’s temperature.

Thanks to humans, the atmosphere has 50% more planet-warming carbon dioxide today than it did before the industrial era. Those gases will continue raising Earth’s temperature for years.

Solid aerosols from the Arctic "didn't look like anything we had ever seen in the literature, in the Arctic, or anywhere else in the world."

The CDC’s updated mask guidelines say that cloth masks offer the least protection from COVID-19. Differences in the materials masks are made from and the ways they fit are the reason.

Air-ventilation upgrades have been badly needed in U.S. classroooms since long before the pandemic. Low-tech filtration systems that cost about the same as a textbook per student can make a big difference.

Is it time to take drastic steps to modify Earth's climate to avoid catastrophic warming? A panel of experts says the idea deserves study.

How well your mask works depends on how well it fits. Wearing two snug masks made of different materials offers 95% protection from exposure to aerosols that could contain the coronavirus.