As a planet in the habitable zone around the sun, Earth consists of several reservoirs that are characterized by profoundly different chemical compositions. The course introduces System Earth from a chemical perspective: what are the different reservoirs, and how do they interact with each other. Trace elements and radiogenic isotopes can be used as tracers for processes in the ‘rock cycle’.
Environmental conditions at the Earth surface are determined by long term processes: formation of continents, the carbonate buffer of the ocean basins, and the composition of the atmosphere. Whereas it is clear that for much of the time span known from the rock record, i.e. ca 4 billion years, surface temperatures have allowed the presence of liquid water, there is some argument as to the actual temperature levels.
Similarly, during these 4 billion years, the chemical composition of the oceans and atmosphere has shown a long term trend of slowly increasing oxygen contents as the result of photosynthesis at first from cyanobacteria and in the last 0.5 billion years from multicellular plants.