Abstract
Climate models, sometimes referred to as earth system models, aim to simulate the physical, chemical and biological processes that influence climate. They can only provide a rough approximation of the reality of these interactions. Although our understanding of these processes has progressed considerably over the last thirty years, and computing capacity has increased by several orders of magnitude, enabling us to achieve ever finer spatial resolutions, it is still necessary to use parameterizations to describe the many processes at work on scales finer than the resolution of the models. Given the many approximations and differences between model results, can we trust the results of climate simulations ?