Earth System Models are highly sophisticated computer models of the physical, chemical and biological processes that make up our planet. They are a key tool in predicting the climate change. Integrated Assessment Models tie physical changes in the climate to economic and social effects. Traditionally, Earth System Models (ESM) and Integrated Assessment Models (IAM) are loosely coupled through a static, unidirectional, asynchronous way. The work presented by this paper develops a novel framework that couples an ESM and a spatially disaggregated IAM in a dynamic, bidirectonal and synchronous way. This work represents a significant advance towards tight, bi-directional coupling between the Earth and Human systems. The tools developed here provide a blueprint for future studies seeking to identify precisely who is affected, where, and when by climate change—an essential step toward designing politically feasible and effective policies.

Increasingly, new supercomputers depend on GPUs for the vast bulk of their processing power. This makes the effective exploitation of GPUs an imperative across geoscientific modelling. This paper presents the port of a full numerical weather prediction system to GPU. It provides an excellent example of how such a port can be achieved in practice while delivering significant performance benefits. As such, this work offers particularly valuable guidance for the wider modelling community.