EARTH SYSTEM SCIENCE 433 Figure The cyclic processes and fluxes between major reservoirs on the Earth Reproduced with permission from Jacobson MC, Charlson RJ, and Rodhe H (2000) Introduction: Biogeochemical cycles as fundamental constructs for studying Earth system science and global change In: Jacobson MC, Charlson RJ, Rodhe H, and Orians H (eds.) Earth System Science, pp 13 San Diego: Academic Press tool in the study of climate change, a topic of great current concern In particular it focuses attention on how anthropomorphic activities, such as the combustion of fossil fuels and deforestation, may have fed back into atmospheric systems, and hence affected global climate (see Palaeoclimates) Moving from the practical to the theoretical, Earth system science has brought about a decline in the reductionist approach to science in general and to geology in particular (Reductionism is the process of knowing more and more about less and less.) In its infancy geology was advanced by natural philosophers (the term ‘scientist’ was not popularized until 1858 by Huxley) who were polymaths It was relatively easy to be a polymath in the nineteenth century, because the pool of scientific knowledge was limited As the pool of knowledge expanded into a lake, then a sea, and finally an ocean, scientists have had to focus their attention on progressively smaller and smaller areas of knowledge, thus losing sight of the wood for the trees Distinct disciplines of chemistry, physics, life science, and geology have evolved, all with their own specialized subsets Earth system science, by taking a holistic view of the Earth, has had a beneficial effect on the development of interdisciplinary scientific research Concomitant with this, however, has been a decline in the training of geologists who can identify rocks, minerals, and fossils, and map their distribution over the Earth Geology has become disseminated into Earth science University Geology Departments have metamorphosed into Departments of Earth Science, coupled with geography, environmental science, etc These departments no longer produce graduates with focused geological knowledge, but Earth scientists who are Jacks-of-all-trades and masters of none