RAPID-RAPIT

North west Europe has a relatively mild climate in part because of heat pulled north through the Atlantic by the overturning. There is a risk that global warming will cause this circulation to rapidly decrease with consequences involving not only colder winters for Europe but also changes in sea level and precipitation. This project will carry out a risk assessment of rapid changes of the Atlantic overturning. We will use two models of the climate system, HADCM3, the Hadley Centre model used in the IPCC AR4, and CHIME, a global climate model developed at the National Oceanography Centre, Southampton. This has the same atmospheric model as HADCM3 but has a very different structure to the ocean component. Making use of the resources of climateprediction.net we will run a large ensemble of both models to assess the uncertainties in the system. We will then use modern Bayesian statistical techniques to combine model output, data and expert opinion in our risk assessment. The utility of the data from the RAPID-WATCH arrays is an important aim of the project.