Bristol urban integrated diagnostics project. Challenge theme report: Carbon neutral city

Abstract

This report presents the key findings of the Carbon Neutral City theme of the Bristol Urban Integrated Diagnostics (Urban ID) pilot project, one of its four themes and five case studies. Urban ID was one of a small number of projects funded by the seven UK Research Councils and Innovate UK’s Urban Living Consortium to explore sustainability in city contexts. Urban ID brought together researchers from the two universities in Bristol, representatives of Bristol City Council, South Gloucestershire Council, the Bristol Green Capital Partnership, Bristol Health Partners, community groups and companies to explore and co-create means of diagnosing urban sustainability problems and potential solutions.
The carbon neutral city theme explored four key questions:
• What does ‘carbon neutrality’ means for the Bristol Urban Area (and what is the Bristol Urban Area) and over what timescale should such a vision be achieved?
• What are the barriers to decarbonisation across the three scopes of carbon emissions (energy use; energy supply; consumption of goods and services)?
• Can Urban ID co-design top-level aims and aspirations for the Bristol Urban Area in relation to carbon neutrality up to 2050?
• Can carbon neutrality for the Bristol Urban Area include ‘all embodied carbon’ as well as emissions from energy use and supply?
The project team concluded that in order to develop a pathway to carbon neutrality for the Bristol urban area there are several key questions to be addressed:
1) What is the carbon budget for the urban area associated with energy production and use in the city region across different sectors – energy supply, domestic, transport, industrial and commercial?
2) What are the current emissions from scopes 1, 2 and 3 (energy use; energy supply; and consumption of goods and services)?
3) What are the ‘business as usual’ projections for emissions to 2030 and 2050 and how do these differ from a carbon neutral pathway?
4) What mitigation actions are needed in different sectors to ‘zero’ the per-capita emissions value and how can carbon budgets assist with this?
5) What is the embedded carbon in goods and services consumed and items purchased in the urban area and is this included in the carbon neutral definition?
6) What level of carbon sequestration is it appropriate to consider to offset any remaining emissions after mitigation actions across sectors?
7) What are the geographical and economic boundaries of the Bristol Urban Area in relation to the carbon neutrality definition?
8) What is the baseline year and what is the end point/target year for the Bristol Urban Area?
The project reveals significant challenges in attempts to design and implement a pathway to a carbon neutral city, but also offers a range of insights and suggestions as to how the above questions might be addressed.