Terrestrial carbon cycle

The terrestrial carbon cycle and the world's ecosystems are sensitive to climate and, therefore, to future climate change. They are also able to influence climate through numerous biophysical and biogeochemical mechanisms such as carbon storage within ecosystems; land surface albedo, stomatal conductance, or interactions between vegetation and atmospheric chemistry. The world's land surface is also directly affected by human activity such as deforestation or agriculture and, therefore, acts as a driver of climate change in addition to burning of fossil fuels. The TCC group aims to understand these processes and feedbacks with focus on providing policy-relevant advice for climate mitigation and adaptation.

Key aims

• Understand the important feedbacks and interactions of vegetation and carbon-cycle in the climate system
• Improve modelling of vegetation and ecosystem processes and model constraints through comparison with observations.
• Implement vegetation and soil processes in coupled climate and Earth System models
• Quantify carbon budgets associated with climate mitigation targets such as 2C warming relative to pre-industrial

The team

Andy Wiltshire - Research Manager

Eleanor Burke

Spencer Liddicoat

Eddy Robertson

The group has strong research links with the Climate Change and Sustainable Futures research group at the University of Exeter.

National and International Colloborations

The team is involved in international and national collaborative projects including contributing to IPCC assessments and the underlying core research needs of the international community.

CMIP5 was the co-ordinated international climate modelling experiment that provided underpinning results for the ICCC 5th Assessment Report. TCC participated with the HadGEM2-ES Earth System Model.TCC will also participate in the next round under CMIP6

JULES is the underlying land surface model used in our Earth System Modelling. JULES is a community model and TCC is active in collaboration to develop this model and it's use and application in policy relevant research. JULES includes a dynamic global vegetation model, TRIFFID. TRIFFID is our main tool for modelling the global carbon cycle.

LUMIP is an international experiment under the CMIP6 framework with the aim of improving understanding of biophysical and biogeochemical effects on climate.

C4MIP is an international experiment under the CMIP6 framework with the aim of improving understanding of the feedbacks between climate and the carbon cycle.

GCP is an international collaboration with the aim of providing a better understanding of carbon cycle processes.

Current projects

The next generation Earth System Model

(Andy Wiltshire, Eleanor Burke, Chris Jones, Spencer Liddicoat, Eddy Robertson)

UKESM will be the next generation Earth System Model and will replace our current flagship model HadGEM2-ES Our contribution to this project is to better represent the terrestrial carbon cycle through the inclusion of new and updated processes such as an interactive nitrogen cycle, land-use changes and new biogeochemical couplings. In addition, a significant effort is going into better evaluation and model constraints to improve confidence in model projections and its use in climate impact modelling.

Carbon Budgets For Climate Targets

(Andy Wiltshire, Eleanor Burke, Chris Jones, Spencer Liddicoat, Eddy Robertson)

We aim to better constrain estimates of carbon budgets compatible with climate targets such as 2C. One aspect of this is quantify total cumulative anthropogenic emissions in the present day. Through international collaboration we provide model based estimates of cumulative land-use emissions to the Global Carbon Budget 2014. Alongside this it is important to quantify carbon cycle feedbacks to climate change to understand their impact on carbon budgets. A significant activity is therefore to quantify permafrost, land-use emissions and nitrogen effects on the future terrestrial carbon sink. Further to this, negative emissions through technological innovation such as Bio-Energy Carbon Capture and Storage may provide a way of offsetting or reversing anthropogenic emissions with a view of meeting carbon targets.

Permafrost

(Eleanor Burke)

Nitrogen

(Spencer Liddicoat)

Land-Use Change

(Eddy Robertson)

Land-use change can alter surface fluxes of water, energy, momentum, CO2 and trace gasses, and thus is an important driver of climate change. As part of the LUC4C project we are quantifying the biogeochemical, biophysical and net effects of land use change on climate. To help in this task we are currently improving the representation of land use change and management in JULES. A key component of LUC4C is to provide policy relevant information about the effects of land use change on climate.

Multi-model Earth System Model Intercomparison

(Chris Jones)