Physics Colloquium 5th June 2015 delivered by Professor Stephen Briggs The Global Climate Observing System was set up in 1992 to define and advocate for the observations required for climate modelling and prediction in support of United Nations Framework Convention on Climate Change (UNFCCC). It has developed a suite of some 50 Essential Climate Variables (ECVs) which define the observing requirements for climate. Satellite data are relied upon for the primary provision of about half of these parameters, and contribute significantly to the majority of the rest. Space agencies have organised themselves through various mechanisms to provide the relevant ECV observations. Some examples of the types of data which contribute to the ECVs and to the wider provision of data of climate modelling, attributions and mitigation will be presented and the wider aspects of dealing with climate change discussed.