This department undertakes research to understand, assess and project the climate system including the atmosphere and oceans, and the carbon and related biogeochemical cycles as important factors responsive to it. The research, to be conducted by making combined use of data and products from observations and numerical models, is aimed at elucidating the mechanism and causes of various phenomena and events, improving the reliability of analysis and prediction and providing feedback to the progress of observations and numerical models. It will then make assessments and considerations on the current state, as well as changes from the past to the future, of the climate system and of carbon and other cycles, with a view to improve their understanding and utilization for socio-economic development and policy making.