Global carbon cycle and climate change
The LGM refers to the time of maximum extent of the ice sheets during the last glaciation, approximately 20,000 years ago. The 6C project developed new tools to reconstruct the environmental parameters from that period. They also combined analytical records of the sedimentary archive with numerical models. This allowed the research team to identify the mechanisms which controlled the operation of the oceanic carbon cycle. It also enabled them to identify water masses as sinks or sources of atmospheric carbon dioxide (CO2). This gave greater insight into the role and impact of the carbon cycle on changes in climate. Knowledge of the nature and extent of past fluctuations allowed scientists to assess the stability of the modern climate and to predict any future variation. The project's second objective was the study of sediments from the northern Arabian Sea. The aim was to demonstrate that the level of CO2 loss from this area increased significantly around 18 thousand years ago. This in turn may have been a factor in the rise in atmospheric CO2 levels at the beginning of the last glaciation. Scientists believe that the oceans were instrumental in regulating glacial-interglacial changes in atmospheric CO2. However, uncertainty exists over past changes regarding the location and level of oceanic sources and sinks of CO2. The reconstruction undertaken by the 6C project indicated that the northern Arabian Sea has been a source of CO2 to the atmosphere for the last 30 thousand years. The data provided by 6C allows policy makers to achieve a clearer understanding of the natural climate system when deciding on agreements to limit greenhouse gases. It has contributed towards more realistic scenarios concerning the impact of climate change. These are necessary for developing mitigation efforts in the EC, underlining the need to reduce future CO2 emissions.
