The Earth monitoring system was continuously built throughout the 20th century, from its technologic components to the political framework. The several following timelines trace this history by highlighting the major milestones in the emergence of the various actors at stake. One presents the creation of the several observing networks which cover the earth nowadays. Another shows the rise of the institutions and organizations which support the Earth monitoring system. Finally a third one displays the political framework binding this complex network.
You can consult the original visualization here.