Changes in Earth's atmospheric composition are a serious cause of concern for humanity as they impact weather and climate, human and ecosystem health, water supply and quality, agricultural production, and many socio-economic sectors. The most pressing of the related problems include:
- climate change - due to steadily increasing amounts of greenhouse gases, especially carbon dioxide;
- the ozone hole - depletion of the protective stratospheric ozone layer due to chlorofluorocarbons (CFCs) and halons has increased ultraviolet radiation, which in turn is increasing incidences of skin cancer and other diseases; and
- urban air pollution, especially fine particles, is affecting human health.
Global Atmosphere Watch studies the variability and trends in atmospheric compisition and related physical parameters, and assesses the consequences thereof. Advancing scientific understanding in order to address these challenges remains critical. Global Atmosphere Watch also focuses on service delivery in a number of application areas where its data brings added value.
One major aspect of the Global Atmosphere Watch mission is to organize, participate in and coordinate assessments of the chemical composition of the atmosphere on a global scale. In this way, the Global Atmosphere Watch provides reliable scientific information for national and international policymakers, supports international conventions on stratospheric ozone depletions and monitors climate change and long-range transboundary air pollution. Global Atmosphere Watch data are used in the following assessments:
Data from the Global Atmosphere Watch feed several bulletins all available in the online WMO Library and/or on the WMO/GAW Extranet webpage: