Isotopes in climatological studies

The predictions on the onset and extent of the greenhouse effect are imprecise due to the complexity of environmental interactions, and the still incomplete knowledge of global meteorological and climatological mechanisms. In recent years, it has become apparent that a deeper insight into the dynamics of this extremely complex, non-linear system can be gained only by an integrated approach which combines two general directions of research aimed at: Understanding of the present climate. This includes evaluation of trends in observation data; refinement and improvement of the atmospheric general circulation models (GCMs); deeper understanding of the role of oceanic circulation on climate; identification and evaluation of important feed-back mechanisms; evaluation of sources and sinks of greenhouse gases; Understanding of the past climate. This includes better characterization of past climatic fluctuations, with a better definition of causes, timing and amplitude; detailed reconstruction of the global ecosystem behaviour during major glacial/interglacial transitions; elaboration of models directed to meaningful projections of past climatic fluctuations into the future. Environmental isotopes, the distribution of which in natural compounds is governed by environmental conditions, are one of the most powerful tools to investigate the climatic variations and the response of the environment to changing climate. This article briefly shows how these isotopes have contributed to the progress of modern views in climatology and palaeoclimatology. The role played by the IAEA in the collection and elaboration of isotopic data of relevance for investigations related to climate and its history is presented. 2 figs, 2 tabs