The Met Office is the national meteorological office for the UK and comprises the Hadley Centre; which is a world-leading centre for the scientific issues associated with climate change. The main aims of the Hadley Centre are: to understand physical, chemical and biological processes within the climate system and develop state-of-the-art climate and Earth System models which represent them; to use climate models to simulate global and regional climate variability and change over the last 100 years and to predict changes over the next 100 years; to monitor global and national climate variability and change; to attribute recent changes in climate to specific factors; and to understand, with the aim of predicting, the natural interannual to decadal variability of climate. The Met Office has considerable experience in the field of weather, climate and Earth System modelling and has developed a state-of-the-art modelling system for weather prediction and climate research known as the Unified Model. The Met Office performs routinely seasonal, decadal and centennial climate simulations. It has made significant contributions to many European Commission funded research both as a project coordinator and as a partner.