Cambridge researchers advise county council on net zero policy actions

Early-career researchers from across the University have outlined the different paths to net zero emissions for Cambridgeshire, an ambitious goal which will involve full electrification of almost all vehicles, full decarbonisation of the national grid, and large-scale investment in public transport.

The Policy Challenges, a collaboration between Cambridge University Science and Policy Exchange (CUSPE) and Cambridgeshire county council, offers an opportunity for early-career researchers at Cambridge to use their skills to benefit the local community, while honing transferable skills, developing an understanding of local government, and engaging first hand with the interface between evidence and policy.

Over a six-month period from March to September 2019, two teams of researchers investigated questions on Cambridgeshire’s carbon footprint raised by the council, and provided evidence-based recommendations on how to adapt policies in order to deliver the county’s decarbonisation goals.

One team addressed the broad question of how Cambridgeshire can reach the UK’s recently-adopted net zero emissions target by 2050, while the second focused on policies to reduce transport emissions, improve air quality and reduce congestion.

“The CUSPE Policy Challenges are a fantastic opportunity to learn about the interactions between local and national government and contribute to evidence used as a basis for new policies. I would recommend them for all those interested in science policy,” said James Weber, a member of the team and a PhD candidate in the Department of Chemistry.

The 2020 round of the CUSPE Policy Challenges will be launched in February 2020: interested researchers can attend the launchevent at Jesus College on Wednesday 26^th February, and can apply to take part by midnight on Friday 6^th March.

Net zero Cambridgeshire

Based on the most recent data at the time of analysis, greenhouse gas emissions for Cambridgeshire and Peterborough amounted to 6.1 megatonnes CO₂-equivalent in 2016, a reduction of 26% since 2005. Nearly 90% of these emissions come from just three sectors: transport (39%), commercial services and industry (27%), and domestic buildings (21%). Agriculture and waste management account for a further 7% and 2% respectively.

To investigate how these emissions levels can be reduced to net zero by 2050, the researchers performed a science-based analysis of all possible opportunities for emissions reductions, in line with two future scenarios: a 2050 baseline scenario which assumes no further actions are taken other than those already legislated or planned at national level, and a second 2050 ambitious scenario which assumes aggressive decarbonisation actions are taken at both national and local authority levels.

Their results show that a 90% reduction in Cambridgeshire’s county-level emissions is possible by 2050 through the ambitious scenario, but will require far-reaching and aggressive mitigation actions. “For progress to be made, action has to be taken across all sectors, but with transport, housing and commercial buildings the major targets,” said Sarah Nelson, another member of the research team, and a PhD candidate in the Department of Engineering.

For transport, this means 91% of heavy goods vehicles (HGVs), and 100% of cars, large goods vehicles (LGVs), buses and motorcycles need to be electric by 2050. In addition, policies to encourage a shift away from cars to walking, cycling and public transport will be required.

To decarbonise domestic buildings meanwhile, a large-scale rollout of low-carbon heating technologies, such as heat pumps and district heating, will be required. Implementing these technologies is also crucial to decarbonise commercial services and industry, a sector which is heavily reliant on natural gas and solid fuel use.

The commercial services and industry sector also dominates demand for electricity, so reducing emissions will also require full decarbonisation of the national grid. The report also emphasises the need for deployment of carbon capture and storage (CCS) at waste incineration plants and aggressive methane capture at landfill sites, to cut emissions from waste management.

Reducing Transport Emissions

The second team of researchers produced an additional report, specifically addressing Cambridgeshire’s emissions from the transport sector. Based on case studies of similar-sized cities across the UK and Europe, they investigated which policies have worked elsewhere to reduce transport emissions, while simultaneously reducing air pollution and congestion.

Their findings show that local policies to stimulate a modal shift away from car use to walking, cycling and public transport yield faster emissions reductions than vehicle electrification, but the introduction of clean air zones and charging schemes to encourage the uptake of electric vehicles is also crucial to fully decarbonise the transport sector. Based on these findings, they suggest a minimum goal of 60% of journeys to be made on sustainable modes of transport by 2030, and a minimum of 60% of new car sales to be electric by 2030.

Closing the gap to net zero

The net zero report also shows that, even if all suggested actions in the ambitious scenario are implemented, 10% of current emissions from difficult-to-decarbonise sectors will still remain in 2050. Agriculture, which only makes up 7% of Cambridgeshire’s current emissions, will account for 40% of those remaining emissions by 2050, resulting from livestock and fertiliser use. Heavy industry and domestic buildings account for a further 23% and 19% of residual emissions by 2050 respectively, in part due to hard-to-decarbonise homes which cannot be disconnected from the gas grid.

Closing the gap to net zero by 2050 will therefore require additional ambitious actions, beyond the ambitious scenario, to reduce those final 10% of emissions to zero. The researchers find that forestation has the potential to play a key role in this, by sequestering between five and 13 tonnes of CO₂ per year per hectare of trees planted. However, sequestering the full 10% of residual emissions would require planting an area of 34,000 hectares, roughly 11% of all land in Cambridgeshire. A combination of other approaches, including demand reduction, bioenergy with CCS, and direct air carbon capture, will also be essential to reach net zero.

These findings are in line with the Committee on Climate Change’s recent UK-wide net zero report, which also emphasises future reliance on negative emissions technologies such as CCS. However, many of these technologies are currently still in early stages of development, and have not yet been deployed at the scale required.

Finally, the report also finds that emissions from peatland, currently not accounted for in emissions inventories, could increase Cambridgeshire’s carbon emissions by as much as 90% if correctly included in reporting. However, by prioritising and investing in peatland restoration and preservation, Cambridgeshire has the potential to turn peatland from a net source of emissions into a net sink, contributing to its carbon sequestration efforts and net zero target. Since the majority of English peatland is located in Cambridgeshire, the county has a real opportunity to become a leader in peatland restoration, and have an impact on climate change mitigation worldwide.

A bold response to the world’s greatest challenge

The University of Cambridge is building on its existing research and launching an ambitious new environment and climate change initiative. Cambridge Zero is not just about developing greener technologies. It will harness the full power of the University’s research and policy expertise, developing solutions that work for our lives, our society and our biosphere.