Greenhouse gas removal could make the UK carbon neutral by 2050, but immediate action is required
A joint report by the Royal Academy of Engineering and Royal Society, with input from the University of Southampton, presents an ambitious plan for how the UK can lead the way in deploying greenhouse gas removal (GGR) technologies to achieve net-zero carbon emissions by 2050.
It is the first time that a range of GGR technologies have been assessed for their real-world potential in being used together to meet climate goals in the UK over the next 30 years.
The report’s authors, including Southampton’s John Shepherd , Emeritus Professor of Earth System Science state that while the UK’s first priority must be to maintain efforts to rapidly cut greenhouse gas emissions, GGR technologies have a role to play in counteracting emissions from aviation and agriculture, where the scope to completely reduce emissions is limited. However, to meet climate targets significant action is essential, starting now. Bringing the UK to net-zero emissions in 2050 will require annual removal of an estimated 130 megatonnes of CO2, even with stringent reductions in emissions.
The report also considers the global picture and outlines a scenario in which a portfolio of GGR technologies can be implemented together to achieve carbon removal across the world by 2100 to meet the goals of the Paris Agreement. Biological solutions like planting trees will become saturated by the end of the century and other GGR technologies will need to be developed and used in the longer term.
The technologies discussed in the report range from well-known and ready to deploy methods, such as forestation, to more speculative technologies like direct air capture, which aims to use chemical processes to remove CO2 from the atmosphere.
Each technology is assessed on its readiness for deployment in the time scale required, potential for scalability, costs, environmental and social impacts and how much of a ‘dent’ it can make in removing excess carbon to meet the targets.
"Prevention is better than cure, so reducing emissions of CO2 is still a better bet than removing it from the air after it has been released,” said Professor Shepherd. “However, CO2 removal technologies are likely to be very useful later this century, to supplement emissions reductions, and compensate for intractable emissions once all other emissions have been eliminated.
“They will also be essential if we eventually decide that the CO2 level remaining in the atmosphere needs to be reduced too,” Professor Shepherd continued. “There are several promising techniques that now need to be further researched and developed, so that they can be deployed when we need them, and there are many opportunities for the UK if we are prepared to invest in them.
"In general, use of the methods based on forests and soil carbon could be commenced within a decade, but their capacity would potentially be fully utilised by mid-century,” Professor Shepherd concluded. “Other methods with greater long-term potential, such as direct air capture and enhanced weathering, therefore also need to be developed so that they can be deployed at large scale after that.”
The UK 2050 net-zero scenario
GGR technologies suitable for the UK to use to meet net-zero emissions by 2050
- Ready to use GGR methods such as forestation, habitat restoration, soil carbon sequestration, and building with wood or carbonated waste could provide just over a quarter of the target to reach net zero emissions.
- Biochar, enhanced terrestrial weathering in agricultural soils, direct air capture (DACCS), and bioenergy with carbon capture and storage (BECCS) could contribute to the rest of the 2050 target.
What we need to do to achieve net-zero emissions in the UK
- Rapidly increase forestation to 5% of UK land, restore wetlands and salt marshes, and store more carbon in farmland;
- Establish an incentive or subsidy system to encourage farmers to use their land to store carbon. This could be part of the framework that replaces the Common Agricultural Policy after the UK leaves the EU;
- Encourage changes in building practice to use wood and cement manufactured with carbonated waste;
- Develop better ways of monitoring the effectiveness of GGR technologies;
- Pursue research into the potential of longer term GGR technologies such as enhanced weathering, biochar, BECCS and DACCS;
- Capitalise on the UK’s strengths in engineering and industry to establish the infrastructure required for the storage of CO2.
How to meet the Paris Agreement using GGR technologies
The report also calls for action in a number of key areas in order to meet the overall goals of the Paris Agreement.
- Continue and increase global efforts to reduce emissions of greenhouse gases;
- Implement a global portfolio of GGR technologies now to meet the goals of the Paris Agreement;
- Build carbon capture and storage infrastructure, essential to meeting the scale required for achieving climate goals;
- Encourage investment in the development and piloting of GGR projects to assess their real world potential and understand any environmental and social impacts;
- Establish incentives, for example carbon pricing, to pay for removal of CO2 and encourage business to use a wide portfolio of GGR technologies;
- Establish a framework to govern use of GGR technologies that addresses sustainability and engages the public;
- Build GGR into regulatory frameworks and carbon trading systems;
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Establish international science-based standards for monitoring the effectiveness of GGR technologies and their environmental impacts.