It has become increasingly clear that humans are changing the chemical composition of the atmosphere in ways that can affect conditions at the Earth's surface – with potential consequences for all Earth's inhabitants. At the core of CSL's research today is the desire to understand atmospheric processes underlying some of the most challenging environmental issues of our time: air quality, climate, and the stratospheric ozone layer.
Greenhouse gases emitted from natural and human-related activities affect climate, and the climate system is warming. Human activities, such as combustion of fossil fuels, release gases and particles that can form harmful pollution in the troposphere, the atmospheric layer nearest to Earth's surface. Poor air quality prematurely kills more than 60,000 people in the United States every year, according to the U.S. Environmental Protection Agency. And in the stratosphere, a "blanket" of ozone – the "ozone layer" – shields us from the harmful effects of the Sun's ultraviolet radiation. Some chemicals released into the atmosphere by people can deplete this protective ozone layer, which in turn can lead to crop damage, harm to natural ecosystems, and skin cancer. These global environmental challenges motivate CSL research.
CSL also assesses the current state of scientific understanding on these three topics and interacts with those who use this information as the scientific basis for decisions – within NOAA, in the United States, and around the globe.