Steven studies how the various processes in the atmosphere conspire to establish climate, how these processes might be expected to control the way climate changes, and how the atmosphere will ultimately interact with the oceans and other components of Earth. Clouds, water vapour and atmospheric convection (for example, storms) in particular remain poorly understood in many respects, but are very important not only in bringing rain locally but also to global climate. These topics are studied by way of theoretical modelling, analysis of detailed simulations of physical processes, and statistical methods applied to observations.