2010 Appleton medal and prize

Dr Myles Allen

University of Oxford

For his important contributions to the detection and attribution of human influence on climate and quantifying uncertainty in climate predictions.

Dr Allen is an outstanding Climate Physicist who has made major advances in the understanding and quantification of the role of uncertainty in predictions of future climate change, and has developed powerful techniques for detecting signs of climate change in observational data. He is especially noted for his vision and leadership in conceiving and bringing to fruition the Climateprediction.net project, the largest climate prediction experiment yet to have been performed.

Rapid changes in the Earth’s climate system, brought about by human activities and industrial development, arguably pose some of the greatest challenges to Society at the present time. But because of the extreme complexity of the climate system and its erratic natural variability, it is very difficult to separate cause and effect, and hence, to evaluate the impact of any one cause on the risk of extreme weather events and other consequences of climate change. During the past 15 years, Dr Myles Allen has sought to apply a combination of clear-sighted physical intuition and rigorous mathematical and statistical analysis to the identification and attribution of changes in the climate system, both in the analysis of the observed behaviour of the climate and in numerical simulation models. This is widely recognised as a very important approach, (a) for a quantitative understanding of anthropogenic climate changes, and (b) for evaluating the impact of proposed responses and measures to ameliorate their effects. Dr Allen’s reputation in this area has been widely recognised internationally, not least by his prominent roles in the 3rd and 4th Assessment Reports of the Intergovernmental Panel on Climate Change.

Of particular note has been his leading role in the pioneering application of novel and innovative distributed computing methods to make use of computing resources provided voluntarily by the general public on a massive scale in the Climateprediction.net initiative. This has enabled his group to carry out ensembles of climate prediction simulations using a state-of-the-art numerical climate model on an unprecedented scale, in which parallel simulations are carried out, subject to variations in either initial conditions or model parameters, with tens of thousands of participants taking part so far. The ability to carry out systematic ensemble simulation studies on this scale is crucial to be able to investigate systematically the intrinsic uncertainties in numerical climate prediction. Advanced climate models are extremely complex nonlinear systems and require the specification of a large number of physical parameters, many of which cannot be quantified accurately from physical measurements of the climate system. So very large ensembles are necessary to explore such a multi-dimensional parameter space. The success of Climateprediction.net has also had an extremely important added benefit of actively engaging members of the public throughout the world in climate research, and in providing an outstanding opportunity for public engagement and education about the physics of climate.