Understanding and incorporating biogeochemical processes and their feedbacks in climate models.
We have long realised that the climate system is driven by more than the purely physical processes (such as wind, clouds, land surface, oceans and ice) that have conventionally been modelled. Specifically the concentrations of major greenhouse gases and aerosols are not only affected by man-made emissions, but are involved in chemical reactions and interactions with the biological components of the Earth system. The importance of adding biological and chemical components to a climate model is that many of the interactions are strongly linked to climate. Hence, a changing climate will affect the concentrations of greenhouse gases and aerosols and so feed back on to the climate.
HadGEM2 is the first Met Office Hadley Centre model to include Earth system components as standard. The extra components that have been added to the physical model include a terrestrial carbon cycle; ocean biology, and tropospheric chemistry. The figure shows the links between them.
To understand and model components of the Earth system and the links between them.
To quantify feedbacks on climate through the Earth system interactions.
To simulate the future evolution of the climate incorporating Earth system feedbacks.
HadGEM3-ES: Inclusion of Earth system components within HadGEM3.
UKCA: Tropospheric and stratospheric chemistry and aerosols within the climate model.
COMBINE: EU project on earth system modelling.