Perspectives on global change science: isotopes in the earth system, past and present

A brief outline of the history of changing perspectives on the build up of greenhouse gases in the atmosphere is followed by an exposition of some of the key contemporary research issues within Global Change Science. Paramount among these issues is the need for a quantitative understanding of the complex interactions between atmosphere, oceans and the terrestrial biosphere. Central to achieving this understanding are global monitoring networks that include measurements of stable isotopes, since from these, the functioning of the hydrological cycle and the exchanges of carbon between the major components of the Earth system may be better characterised, quantified and traced through time. Concrete proposals for the establishment and enhancement of such networks are laid out. At the heart of these proposals and the scientific precepts upon which they rest, lies the belief that Global Change Science is not only of vital concern for the future and but also provides a stimulating and attractive framework for a broad spectrum of challenging research within the natural sciences.