Carbon budgets and pathways

A global carbon budget is the limit on how much carbon dioxide the world can emit cumulatively over a set period of time, while still having a likely chance of limiting global mean temperature to a specified level.

A carbon budget for a rise of 2°C is considered a threshold for dangerous climate change. Because of the world’s high cumulative emissions to date, the remaining carbon budget is extremely small.

The key questions in this area are; how to allocate the remaining global carbon budget between countries and between economic sectors fairly; and how countries and sectors can move towards low-carbon pathways from their current high-carbon course.

Tyndall Manchester has championed a pragmatic allocation of carbon budgets between countries, based on the principles of science and equity. We are leading research on rapid emission cuts through mature technologies and reductions in demand for aviation, road transport and shipping.

Our researchers have developed 2°C carbon budgets for high-level policy-making in countries such as the UK and Russia and sectors such as aviation and shipping. We have emphasised the risks of relying on speculative negative-emission technologies instead of immediate emission reductions.

The 2015 Paris Agreement committed all signatories to rapidly reduce their emissions of greenhouse gases in line with limiting the global average rise in temperature to between 1.5°C and “well below 2°C.”

Energy from coal, oil and gas fuelled the industrial revolution and continue to be the principal energy sources underpinning society. Delivering on our Paris commitments requires a transformation from our current high carbon industrial, transport and domestic energy systems to zero carbon alternatives by the middle of this century.

Our researchers are opening up a new space where opportunities and obstacles to deliver rapid and deep decarbonisation in-line with the Paris commitments can be analysed and discussed. We have been at the forefront of revealing the scale of the decarbonisation challenge and the reliance in most scenarios on highly speculative technologies and the inequitable treatment of poorer low-emitting nations. Building on all of this, we have a long history of developing 2°C energy scenarios with a real focus on energy demand, as well as low carbon energy supply.

Social resilience is the capacity of people and communities to deal with external stresses and shocks. Research in this area explores resilience to the challenges that systems and infrastructure face due to climate change and how this contributes to community preparedness to risk and uncertainty.

Tyndall Manchester is investigating resilience to changes in electricity provision to better understand strategies that can help communities prepare for such events - including household preparedness for direct impacts of extreme weather events on electricity provision. Social responses to long-term electricity shortages and measures such as rolling power outages are explored in a study of power cuts in Beirut. The central role that communities and infrastructure have in such precarious conditions is also explored through the 'Following the Wires' project, which brings together insights from filmmaking and anthropology to provide a broader understanding of resilience.

The findings from this research highlight the importance of meanings, practices and processes to achieve resilience at the household level.

Many cities and regions around the world are committing to carbon emissions targets in line with the Paris Agreement to “hold the increase in global average temperature to well below 2°C above pre-industrial levels and pursue efforts to limit the temperature increase to 1.5°C".

The targets and pathways set by cities and regions need to be consistent with the global carbon budgets set by the Intergovernmental Panel on Climate Change (IPCC), and made on the basis of science and equity.

This raises questions such as: How can global and national carbon budgets be allocated to cities and regions; and what level of ambition can cities and regions realistically adopt?

Tyndall Manchester applies a holistic approach to downscale carbon budgets from global to national and local regions. For this global carbon budgets are apportioned to local regions by allocating emissions from deforestation, cement process, aviation and shipping and other remaining energy sectors to appropriate levels.

Our researchers are providing recommendations to regions (Scotland, Wales) and local authorities (Greater Manchester) in the UK and Sweden.

By generating energy from biomass with carbon capture and storage (CCS), carbon dioxide taken up by the biomass via photosynthesis can be removed from the atmosphere if it is captured during energy conversion; this is referred to as negative emissions.

Negative emissions may offset emissions from sectors, which are difficult to decarbonise (such as aviation and agriculture) or may help society to achieve its carbon budgets and targets. However, this would require bio-energy with CCS (BECCS) to be implemented at a very large scale, which would have wide ranging implications.

Tyndall Manchester is part of a consortium exploring the feasibility of BECCS for greenhouse gas removal, looking across a set of full BECCS life cycles, from the land where biomass is grown through to the storage of the carbon dioxide during energy conversion or fuel production.

Our work has analysed key assumptions behind BECCS in global integrated assessment models, which inform climate policy, in relation to current academic understanding.