An Imperial-led study will focus on how the world can meet climate change targets by removing greenhouse gases from the atmosphere.

The project is part of a new £8.6m UK research programme on greenhouse gas removal announced this week.

The UK has committed to the 2015 Paris Agreement, which seeks to keep global temperature rise below 2°C pre-industrial levels. As well as reducing the amount of greenhouse gases being emitted, actively removing them from the atmosphere could help reach this target.

There is intensive research into methods for greenhouse gas removal, but questions remain around their feasibility, as well impacts on society and public attitudes. To help answer these questions, the £8.6 million research programme will evaluate the potential and wider implications of a variety of options.

The programme is jointly funded by NERC, the Economic and Social Research Council (ESRC), the Engineering and Physical Sciences Research Council (EPSRC) and the Department for Business, Energy & Industrial Strategy (BEIS). The Met Office and the Science and Technology Facilities Council (STFC) are providing in-kind support. 

Dr Niall Mac Dowell, from the Centre for Environmental Policy at Imperial, will lead a £2 million project that will investigate the options for greenhouse gas removal in different regions, and how these regions can work together to meet global climate goals. Hayley Dunning talked to him about his vision for the project.

What are the current options for removing greenhouse gases?

One of the most discussed option is bio-energy with carbon capture and storage (BECCS). This involves burning plants for fuel and then capturing the carbon emissions from this process and permanently storing them underground.

Plants draw carbon dioxide (CO₂) from the atmosphere as they grow, so by burning them and storing the carbon that is emitted underground, we are removing greenhouse gasses from the atmosphere – creating negative emissions.

Alongside these technologies, removal of greenhouse gases from the atmosphere can be increased, for example by the direct capture of CO₂ from the atmosphere, by planting trees as part of the process of reforestation.

Another option is increasing the natural process of weathering, where carbon dioxide in the atmosphere reacts with certain rocks on the surface. However, the available evidence prioritises BECCS as a key option.

What are some of the issues around using these technologies effectively?

BECCS is being demonstrated in the USA, most notably at the Illinois Industrial Carbon Capture and Storage Project which has recently started and is expected to remove one million tonnes of CO₂ from the atmosphere per year. However, this is still small scale compared to what is required to achieve our climate change targets.

One thing that that is vital to accelerate large-scale adoption by countries would be for policy makers to explicitly value this service of atmospheric carbon dioxide removal. This would create a market incentive to develop the technology and its capacity.

What will you be doing in your project?

We will work to determine how BECCS can be used in sustainable ways tailored to each regional situation. For example, it is important where the biomass comes from – if biomass burned in the UK is grown on the other side of the planet, it won’t be nearly as sustainable as if it were grown locally. Other factors which affect the sustainability, or otherwise, of biomass include the way in which it is cultivated, harvested and transported. Each of these elements is core to our study.

Different options will also work better in different places. Installation of BECCS plants might work well in the UK as we have ample space to store CO₂ in the North Sea, but large-scale reforestation might be a better option where CO₂ storage resources are limited, but there are good conditions for afforestation.

This feeds into questions about how international co-operation can reduce the cost of reaching global climate goals. At the moment, there are global climate goals and then each country works out an individual plan for their own targets. A better solution might be to exploit the technological options best suited for each region, so that the overall global goal is reached collaboratively.

We want to produce papers on regional options, roadmaps and opportunities for collaboration, but also to establish the UK as thought leaders in this area. Our work is intended to feed into the next Intergovernmental Panel on Climate Change (IPCC) reports, and be available to world leaders debating at the next COP climate conference.

Who are you working with?

Our project is in collaboration with organisations such as the International Institute for Applied Systems Analysis (IIASA) in Vienna and the International Energy Agency, universities such as MIT and Colorado School of Mines, industry partners, and the government Department for Business, Energy & Industrial Strategy.