Current estimates of future global climate change rely on coupled models of the climate system. These models are both a measure of our level of understanding of coupled processes occurring in nature and of our ability to simulate the possible changes in these processes due to increased CO2and trace gases with computer models. Central to coupled models is air‐sea interaction, but processes involving the cryosphere, biosphere, atmospheric chemistry/radiation, and land surface are also intimately involved. Monitoring and analysis of observations are critical for understanding and interpreting results from the coupled model