How and why will climate variability change in a warmer world?

Robust projections of future climate will help nations to effectively adapt to climate change. Producing such risk-based projections requires both an understanding of the long-term response to changes in external factors (such as greenhouse gases), and also of how the climate for that region is expected to vary naturally.

Much progress has been made in understanding the important role of atmosphere and ocean circulations for producing past natural variations in climate. However, determining whether the characteristics of these variations may change as the climate warms has not been comprehensively examined.

This project will examine how and why the natural variations in climate may change in a warmer world, determining the physical processes responsible and focusing on the Atlantic, Arctic and surrounding land regions. For example, as Arctic sea-ice melts, the surface ocean will become more exposed, lowering the albedo and fundamentally altering the exchanges of heat and water between the atmosphere and ocean. Further south, the warming of the surface waters in the North Atlantic will modify the ocean stratification and the amount of mixing. Both of these effects are likely to alter deep ocean circulations which influence the climate over Europe, Africa and the Americas.

A suite of novel climate model simulations representing past, present and future climates will be compared with existing observations to produce an improved understanding of these issues.