A growing body of research now confirms that the Montreal agreement averted at least one catastrophic form of climate change, even if others still loom. "The Montreal Protocol is a major success story," says William Randel.

A team led by NCAR's Jim Smith has found that aminium salts make up as much as half of the mass of newly formed particles in places as diverse as Atlanta, Mexico City, northeast Colorado, and Finland.

NCAR researchers are increasingly adopting an innovative tool for statistical computing and graphics. Called R, this community software project is the statistics equivalent of the LINUX movement.

Preliminary research at NCAR suggests that biological particles may contribute significantly to the mass of organic carbon stored in atmospheric aerosols. The study is an important step for scientists.

When it comes to global air pollution, what goes around comes around. Air pollution from factories, traffic, and power plants in Asia wafts over the Pacific Ocean to the United States, while pollutants produced in the United States wind up in Europe.