Cambridge Centre for Climate Science

The scope of research into climate and climate change in Cambridge is very broad indeed. The focus in CCfCS is on scientific research (mathematical, physical, chemical and biological) relevant to Working Group 1 of the Intergovernmental Panel on Climate Change. For Cambridge research into socio-economic aspects of climate see the Cambridge Centre for Climate Change Mitigation Research.

Atmosphere-Biosphere Interactions

The terrestrial biosphere influences the atmosphere through many processes. Some of the most important include the exchange of CO₂and the partitioning of surface energy into latent and sensible heat fluxes. The sensitivity of the terrestrial biosphere to climate and atmospheric chemistry result in the biosphere and atmosphere behaving as a coupled system, with the potential for strong positive and negative feedbacks. Anthropogenic disturbance of natural ecosystems, climate, and atmospheric chemistry is currently changing this coupled system over much of Earth’s land surface. Understanding the coupled behaviour of the terrestrial biosphere and atmosphere is therefore a key research priority, not least because of the major role of terrestrial ecosystem in the global carbon cycle, but also because of the significance of surface characteristics for local and regional climate through biogeophysical effects.

The HYBRID model is a detailed global model of terrestrial ecosystem dynamics. It is being used to understand the influence of climate and atmospheric CO₂ variability on the distribution of vegetation types, productivity, and carbon stored in plants and soils. Components have been used to develop the land surface model of the GISS GCM modelE, and the model is currently being used in a number of projects, including IPCC assessments of climate change impacts for the IPCC Fifth Assessment Report (AR5) and for various projects within the GREENCYCLESII Marie Curie Initial Training Network

Ocean and sea ice dynamics

The ocean is a dynamic and important part of Earth’s climate system. Scientists across CCfCS study ocean circulation using a combination of observational, theoretical, and computational approaches.

CCfCS scientists use the full spectrum of theoretical, observational (e.g. ship-based, using autonomous floats), laboratory, and numerical modelling approaches to better understand the circulation and biogeochemistry of the world’s oceans.  Many scientists across CCfCS are involved in various aspects of oceanography and sea ice

Cryosphere and Sea-Level Rise

The cryosphere plays an important role in global climate processes. Ice permanently covers 10% of the land surface, with only a tiny fraction occurring outside Antarctica and Greenland. Ice also covers approximately 7% of the oceans in the annual mean. In midwinter, snow covers approximately 49% of the land surface in the Northern Hemisphere. An important property of snow and ice is its high surface albedo. Because up to 90% of the incident solar radiation is reflected by snow and ice surfaces, while only about 10% is reflected by the open ocean or forested lands, changes in snow and ice cover are important feedback mechanisms in climate change. In addition, snow and ice are effective insulators. Seasonally frozen ground is more extensive than snow cover, and its presence is important for energy and moisture fluxes.

Recent observations and analyses of changes in ice include shrinkage of mountain glacier volume, decreases in snow cover, changes in permafrost and frozen ground, reductions in arctic sea ice extent, coastal thinning of the Greenland Ice Sheet exceeding inland thickening from increased snowfall, and reductions in seasonally frozen ground and river and lake ice cover. Based on analyses of tide gauge and satellite altimetry measurements, the rate of change of 20^th century global sea level has been assessed as 1.7 ± 0.5 mm yr^–1. Changes in the cryosphere affect not only eustatic sea level, but also regional sea level as a result of glacial isostatic re-adjustment. Likely consequences of rising sea level include increased coastal erosion, degradation of coastal ecosystems such as wetlands and coral reefs, and increased vulnerability of people in low-lying coastal urban areas, atolls and river deltas (especially Asian megadeltas).

Earth System Modelling

Climate scientists across CCfCS use and develop computer models to study the whole range of physical, chemical and biological processes that make up the Earth’s climate system.To help us understand how the Earth system works and to improve predictions of future environmental change, members of CCfCS work to develop and run a variety of state-of-the-art computer models

A collaboration between the UK Met Office and the Natural Environmental Research Council (NERC) is helping to drive the development of a new Earth System Model, UKESM1. This is a truly joint effort, with many of the component systems being designed and coded by NERC research centres and University groups. This includes the British Antarctic Survey (BAS), who are playing a central role in improving the simulation of the cryosphere components (e.g., Southern Ocean, sea ice, ice shelves), and the Department of Chemistry who are building and testing the new atmospheric chemistry and aerosols component.

Of course, observational and theoretical research into the Earth system plays a crucial role in the model development process. To make sure the models incorporate the most up-to-date information from these fields, we maintain good communication channels between the CCfCS partners, and with the wider UK research community, to ensure information is passed onto the relevant developers

Climate scientists across CCfCS use and develop computer models to study the whole range of physical, chemical and biological processes that make up the Earth’s climate system.

Pats Climate Change

Scientists in CCfCS work to understand past climate by collecting, analysing and interpreting sediments and rocks, ice cores and geophysical data, and through modelling.
Understanding how and why climate has changed in the past is crucial for several reasons. The observational record is very short, and does not provide the perspective with which to view recent and future trends. Only by looking at a much longer timescale can we view natural variability, and the response of different parts of the Earth system to perturbations. This applies particularly to processes related to ice sheets and the carbon cycle, which have timescales of centuries to millennia. Finally there are some fascinating questions about the nature of the Earth system that simply require an answer – for example, why does Earth cycle through large swings in climate from a situation with large amounts of ice cover to the relatively mild conditions of today?

Scientists in Cambridge address these issues by collecting, analysing and interpreting sediments and rocks, ice cores and geophysical data, and through modelling. The British Antarctic Survey (BAS) and the Department of Earth Sciences work on marine sediments and ice cores, as well as records from deep time held in geological materials. Scott Polar Research Institute and BAS study evidence for past ice sheet extent. BAS, DAMTP, Geography and Chemistry have all been involved in work that applies state-of-the-art models to past climate changes.