New climate models are zooming in on regional risks

More detailed climate models are helping researchers explore how climate change may affect particular regions and how human actions shape the risks ahead. By Tom Cassauwers From his office on the outskirts of the French city of Toulouse, Roland Séférian literally charts out the future of our planet. Working at the National Centre for Meteorological Research (CNRM), the climate scientist designs models that project future climate change. Among the best known are the models featured in reports by the Intergovernmental Panel on Climate Change (IPCC), the UN body that assesses the science of climate change. These models simulate the entire Earth system by dividing it into a grid of large boxes, known as grid cells. This can make it difficult to capture the smaller-scale processes that shape climate risks in particular places.

Researchers across Europe are developing new Earth-system models to address two related challenges: representing more fully how human activities change the climate, and simulating climate processes more realistically at global and local scales. The latest models Séférian has been working on tackle the first of these challenges. They explore how the climate responds to human activities, primarily emissions and land use change. “We can now also see what might follow from introducing a technology that takes CO₂ out of the air,” he explained. To do this, researchers are improving the links between the atmosphere, land and oceans in climate models. This makes it easier to trace how human emissions move through the Earth system, including the carbon absorbed and released by land and oceans, and how these changes influence the climate. With a background in oceanography, Séférian specialises in how the oceans and other parts of the Earth system absorb, store…