The Global Atmosphere Watch (GAW) is a worldwide system established by the World Meteorological Organization – a United Nations agency – to monitor trends in the Earth's atmosphere. It arose out of concerns for the state of the atmosphere in the 1960s.
The Global Atmosphere Watch's mission is quite straightforward, consisting of three concise points:
The GAW programme is guided by 8 strategic goals:
Moreover, the programme seeks not only to understand changes in the Earth's atmosphere, but also to forecast them, and perhaps control the human activities that cause them.
The original reason for testing the atmosphere for trace chemicals was mere scientific interest, but of course, many scientists eventually wondered what effects these trace chemicals could have on the atmosphere, and on life.
The GAW's genesis began as far back as the 1950s when the World Meteorological Organization began a programme of monitoring the atmosphere for trace chemicals, and also researching air pollution from a meteorological point of view. They were also responsible for monitoring ozone, establishing the Global Ozone Observing System (GO3OS) in 1957, in the International Geophysical Year.
In 1968, the United Nations called for an international conference to address world environmental problems caused by rapid industrialization. At about this time, the World Meteorological Organization set up another environmental research body, the Background Air Pollution Monitoring Network. The conference was held in Stockholm in 1972, and addressed several environmental concerns, namely:
Indeed, it was the World Meteorological Organization's readings and observations that figured prominently at this conference. They had little good news to offer.
The GAW itself was eventually created in 1989 by combining the GO3OS and the Background Air Pollution Monitoring Network. The GAW consists of a worldwide system of observing stations and supporting facilities providing data for atmospheric assessments, and also serving as an early warning system for chemical or physical changes in the Earth's atmosphere which could be cause for environmental concern. Such changes might involve a change in ozone, and therefore ultraviolet, levels, levels of greenhouse gases, or precipitation chemistry, the culprit in the world's acid rain woes.
The GAW consists of a coordinated system of various components, prominent among which are:
More than 65 countries currently host and operate the GAW's global or regional measurement stations. There are also "contributing stations" that furnish additional data. Lately, satellite programmes have also become important to the GAW, providing atmospheric data that complement ground measurements.
These have the job of ensuring that all data produced by the system measure up to international standards. This is achieved by assuring a rigorous adherence to standards established by scientific advisory groups and a strict enforcement of world calibration standards. A number of programmes such as education, workshops, calibration station visits and so on are provided within the GAW programme to enhance the performance of the human component of the GAW. This has become particularly important in recent years as quite a number of stations are now operating in developing countries where further education is often a luxury enjoyed only by a small élite.
The Global Atmosphere Watch currently has five World Data Centres, each administered by its host nation, and each responsible for gathering and storing atmospheric data from measurement stations worldwide, and making it freely available to scientists in a number of different forms.
Scientific Advisory Groups (SAGs) have the job of managing and implementing the GAW programme. This includes establishing data quality objectives and standard operating procedures, and also providing guidelines and recommendations for achieving these things. Measurement methods and procedures also fall within the SAGs' domain. They are also charged with promoting twinning and training in developing countries.