New report presents evidence from across the Greenhouse Gas Removal Demonstrators programme

About the author: Dr Judith Thornton is a Low Carbon Research Fellow at Aberystwyth University. She works on the Perennial Biomass Crops for Greenhouse Gas Removal (PBC4GGR) Demonstrator project. Read more about findings from the PBC4GGR project and the rest of the Greenhouse Gas Removal Demonstrators programme in our new report. 

Why the legacy of the GGR-D programme needs to be based on action

Rapid and drastic cuts in carbon emissions are essential, and future promises of greenhouse gas removal (GGR) cannot be allowed to compromise near term resolve on emissions reductions. However, the amount of climate change that has already happened is causing significant problems worldwide, and so even in an optimistic scenario of extremely low future emissions, using GGR as a way of dealing with historic emissions is highly desirable. Consequently, whilst the GGR-D programme is almost at an end, our need for GGR as a technology is here to stay.   

Land: they’re not making it any more

The five demonstrator projects (perennial biomass crops, peatland management, enhanced rock weathering, afforestation and biochar) are all looking at GGR technologies with a high dependency on land, as opposed to technologies such as direct air capture, or ocean-based GGR approaches. This has created excellent opportunities for collaboration across projects, comparison of the relative merits of GGR technologies for particular land areas and how they might conflict with each other, and some consideration of the idea of ‘stacking’ – implementing more than one GGR on a given parcel of land. Not working in isolation has also meant that all the projects have made progress across a wider range of questions than they might otherwise have done; the social science teams from the projects have collaborated closely with each other, for example, as have the life cycle assessment teams.

Learning by doing

As we come to the end of the programme, thoughts naturally turn to what we do next, both as researchers and as a society. Researchers will always want to increase the sum of knowledge on a subject, and answers to questions invariably lead to more questions. However, given the urgency of action on climate change, it’s good to reflect on what knowledge is essential, compared to what is nice-to-have – in other words, what our no-regrets options would look like in terms of deployment of GGR technologies if we started today.

In the case of perennial biomass crops for greenhouse gas (GHG) removal, we certainly have enough knowledge to deploy the next 10,000 hectares of crops. This is not a very long way towards the 2050 goal of 750,000 hectares, but given that the planted area in the UK has hovered stubbornly around 10,000 hectares for the last 15 years, a doubling of current area is an important first step. If we were to identify sites for this in 2026, prepare the ground and get planting using current levels of expertise and machinery availability, we could feasibly plant 5,000 hectares in 2027 and the same again in 2028. End markets for the crops are already available, and large-scale future markets will develop in the UK’s nascent CCUS clusters, with markets expanding once BECCS becomes widespread. It would be a period when the relatively small pool of contractors, agronomists and growers could begin training others in order to mitigate the skills gap that would need addressing to allow the industry to expand faster in subsequent years. But perhaps the most important benefit of learning by doing is that we would normalise perennial biomass crops amongst both industry and wider society and create some momentum towards what is an extremely challenging 2050 target.

What do researchers do next?

As areas of perennial biomass crops scale up, the types of questions that research will need to answer will also change. For example, whilst we know that both Miscanthus and short-rotation coppice (SRC) willow can prevent soil loss during heavy rainfall events and potentially mitigate flooding, we know very little about whether the benefits seen in small-scale experiments will also be seen when the crops are grown on multiple fields in different areas of a river catchment. We would also be able to address questions relating to potential problems that might arise. We know that in theory, if planted as a mosaic across fields on neighbouring farms rather than as monoculture, biodiversity won’t be negatively impacted or might even improve. But we need evidence from these landscape-scale deployments in order to provide certainty before we scale up further.

Moving from policy to delivery

Much of society is sceptical of GGR technologies, particularly of engineered removals, with the criticism typically being that they have not been demonstrated at scale. The crucial legacy of the GGR-D programme is that we now know enough to implement near-term delivery targets across the suite of GGR approaches to address this very issue.

Photo: Measuring willow in the PBC4GGR demonstrator field at Myerscough College. Credit: Will Macalpine.