Climate Change and Earth-Ocean-Atmosphere Systems

The climate group uses a range of archives and proxies to document past climate change. The aim is to elucidate the processes governing climate change, providing empirical evidence to test theories and models, including those used to predict future climate change. Our evidence comes from archives including marine and lake sediments and ice cores. We have developed a range of chemical, isotopic and sedimentary proxies of the critical parameters needed to describe past climatic states and the processes that force change. Among other topics we use these tools to look at climate change, ocean circulation, biogeochemical cycles and ice sheet changes, with a strong emphasis on glacial cycles and rapid climate change within the last glacial cycle. However we also study earlier periods of Earth History, and more recent climate change and its impact on societies. We have increased the links between workers on marine, ice-core and terrestrial records and promoted collaboration with the climate modelling community. Our isotope-geochemistry laboratories, known collectively as the Godwin Laboratory (link), and facilities are state of the art.

Current research includes:

• Understanding astronomical forcing of climate change records as recorded in oceanic sediments.
• Multi-proxy studies of abrupt climate change in the oceans, and its impacts recorded in ice.
• Sedimentological and geochemical tracers of past deep-sea circulation vigour and its role for changing atmospheric CO₂:
• Use of foraminiferal metal chemistry and the stable isotopic composition of biogenic sediments in palaeochemical studies of ocean temperature and nutrient variations.
• The stability of the Greenland and West Antarctic ice sheets, particularly during past warm periods
• Processes and geochemical fluxes associated with earth-atmosphere interaction in chemical weathering.
• Interactions between geochemistry and microbiology and how these related to  biogeochemical cycling.
• Biogeochemical cycling of stable isotopes and elements in marine and terrestrial systems, with particular focus on the carbon and sulphur cycle.
• The co-evolution of alluvial systems and land plants during the Palaeozoic.
• The sedimentary record of the terrestrialization process.
• Applying geochemical methods for conducting societally relevant research, such as effects of climate change on ancient civilizations and carbon sequestration.

We are also interested in supervising research students in the general fields of seawater, ice core and sediment geochemistry, for example using isotope geochemistry to understand water and chemical budgets of the oceans, and in linking understanding of the chemistry of the modern rivers and oceans to weathering history and palaeoceanography. Studies of modern sedimentation also provide a link to understanding past ocean dynamics. 

We have well equipped laboratories with two multi-collector ICP mass-spectrometers, two solid-source and eight gas-source mass spectrometers, atomic-emission spectrometer, high-resolution ICP-MS, C-H-N analyzer, atomic absorption, Sedigraph, a coulter counter, magnetic susceptibility, X-radiography, cathodoluminescence. Our ice core studies are collaborative with the British Antarctic Survey, also in Cambridge. Thus, we offer topics which incorporate training in geochemical and sedimentological techniques, into research on major current problems in global change and global biogeochemical cycles.

Recent publications in this area.