Interactions between subunits of the global climate-biosphere system (e.g. atmosphere, ocean, biosphere and cryosphere) often lead to behaviour that is not evident when each subunit is viewed in isolation. This newly evident behaviour is an emergent property of the coupled subsystems. Interactions between thermohaline circulation and climate illustrate one emergent property of coupling ocean an...

The spatial patterns, time history, and seasonality of African rainfall trends since 1950 are found to be deducible from the atmosphere’s response to the known variations of global sea surface temperatures (SSTs). The robustness of the oceanic impact is confirmed through the diagnosis of 80 separate 50-yr climate simulations across a suite of atmospheric general circulation models. Drying over ...

Rainfall observations in the Sahel region of West Africa show significant variability at the timescale of decades. Here we explore the mechanisms of this lowfrequency variability using a coupled biosphere-atmosphere model which includes explicit representation of vegetation dynamics. By forcing the model with the observed sea surface temperature (SST) of the tropical Atlantic Ocean during the p...