The Group on Earth Observations was launched in response to calls for action by the 2002 World Summit on Sustainable Development and the G8, which recognized that international collaboration is essential for exploiting the growing potential of EO.
A series of three summits led to the creation of the GEO. The first Earth Observation Summit (July 2003) adopted a Declaration which established an ad-hoc Group on Earth Observations and tasked it to draft a 10-Year Implementation Plan.
The second Earth Observation Summit (April 2004) adopted a Framework Document defining the scope and intent of the Global Earth Observation System of Systems.
The third Earth Observation Summit (February 2005) endorsed the Ten-Year Implementation Plan and formally established the Group on Earth Observations to carry it out.
Membership in GEO is open to all member States of the UN and to the EC. GEO welcomes as Participating Organizations intergovernmental, international, and regional organizations with a mandate in EO or related activities, subject to approval by Members. There are currently 75 Member countries and 51 Participating Organizations (as of December 2008).
The GEOSS 10-Year Implementation Plan was endorsed by nearly 60 governments and the European Commission and is designed to qualitatively improve our understanding of the Earth system, markedly enhancing global policy and decision-making abilities to promote the environment, human health, safety and welfare.
The 10-Year Implementation Plan established the intent, operation principles, and institutions relating to GEOSS, supported by a longer Reference Document which is consistent with the Plan and provides substantive details necessary for implementation.
G8 Hokkaido Toyako Summit Leaders Declaration (8 July 2008):
"To respond to the growing demand for Earth observation data, we will accelerate efforts within the Global Earth Observation System of Systems (GEOSS), which builds on the work of UN specialized agencies and programs, in priority areas, inter alia, climate change and water resources management, by strengthening observation, prediction and data sharing. We also support capacity building for developing countries in earth observations and promote interoperability and linkages with other partners."