The Second World Climate Conference in 1990 called for the urgent establishment of a coordinated climate monitoring system. As a consequence, the Global Climate Observing System (GCOS) and the Global Terrestrial Observing System (GTOS) were established in 1992 and 1996, respectively, under the auspices of FAO, ICSU, UNEP, UNESCO, and WMO. Within GCOS/GTOS the Terrestrial Observation Panel for Climate (TOPC) was created to design a global observing strategy and set in place a Global Terrestrial Network (GTN) for all Essential Climate Variables (ECV) in the terrestrial domain in support of the United Nations Framework Convention on Climate Change (UNFCCC). The GTN is a system of networks that provides an umbrella for existing and operational monitoring services. It should facilitate the exchange of information and address issues such as data access and availability as well as the standardization of measurement methods.
The Global Terrestrial Network for Glaciers (GTN-G) is jointly run by three operational bodies: the World Glacier Monitoring Service (WGMS), the US National Snow and Ice Data Center (NSIDC), and the Global Land Ice Measurements from Space (GLIMS) initiative. A GTN-G Steering Committee was established in 2009 to coordinate, support, and advise these three operational bodies concerning the monitoring of glaciers and ice caps.
Schematic overview of the Global Terrestrial Network for Glaciers (GTN-G) and its interactions with international organizations, scientific community, national agencies, the media, and the general public. The figure shows the flow data compilation and dissemination (blue and green arrows, respectively) as well as the main sources of funding (orange dots) and the formal links to international bodies (red and green dots).