Aerosols, small particles in the atmosphere like salt and dust, may offset a third of human-caused climate warming, though their influence is fading.

Flu viruses often enter the body through mucous tissue in the nose. Researchers are developing new ways to protect such areas.

The invasive spotted lanternfly has spread to 17 states and can threaten vineyards. But bats, fungi, dogs and even trees may help control them.