In 1974, scientists discovered that chlorofluorocarbon (CFC) gases used for refrigeration, aerosol cans, and other purposes were destroying Earth’s protective ozone layer. As a result, in 1975 Congress directed NASA to “develop and carry out a comprehensive program of research, technology, and monitoring of the phenomena of the upper atmosphere so as to provide for an understanding of and to maintain the chemical and physical integrity of the Earth's upper atmosphere." NASA thus began monitoring and researching CFCs, ozone, carbon dioxide, and other trace gases, which are gases that account for less than 1% of the atmosphere by volume. Today, these trace gases are known to play important roles in Earth’s atmospheric chemistry, air quality, and climate.

NASA has powerful and precise devices to detect and measure trace gases such as the Ozone Monitoring Instrument (OMI) and the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument. Prime uses for their data include environmental protection, air pollution monitoring, and climate change modeling. Datasets from these instruments are available to anyone and can be easily accessed through Earthdata Search.