The green potential of an industrial past

Emma Summerscales discusses the carbon capture garden project with Dr Pete Manning.

Scientists from Newcastle University are experimenting with gardens down at Science Central to explore an ingenious approach to capturing carbon from the atmosphere. A big part of the project focuses on determining which sorts of vegetation – from grass to green compost and birch seed – have the best ability to sequester carbon in the ground.

An interview with Dr Pete Manning, from the School of Agriculture, Food and Rural Development, provides further insight into the project.

He begins by giving an overview of the science behind the gardens: “Plants, via photosynthesis, assimilate CO2 from the atmosphere and then they release that CO2 when they respire, and that happens both through their leaves and through their roots. They also produce dead organic material and the decomposition of their dead organic matter by fungi and other micro-organisms releases CO2.

“They also undergo a process known as rhizodeposition which exudes carbon from their roots. All three of those processes basically end with the CO2 in the soil environment and that can combine with minerals in the soil to form stable carbonate carbon. It is a way of potentially getting atmospheric CO2 into the ground in a form which is stable and bound up, so it’s a way of sequestering carbon and mitigating climate change.”

With these areas working best on brown-field sites where there is limestone-based crushed concrete or on mineral slags (areas of mineral waste from mine extraction), these carbon capture gardens could be short lived as developers seek to take on the sites. However, as Dr Manning explains, this idea could work alongside development. “You could have pop-up sites. Plants come up, you get a quick carbon fix in the soil and then build on it, that carbon’s not going anywhere. In the meantime you have a green space to be used as recreation or a biodiverse area – we see them as being multifunctional urban spaces.”

Looking to the future, Dr Manning says, “It’s very early days on the research at present, and what we’d now like to do is look at this across a wider range of sites across the UK.” He points out that research also needs to be focused on how much carbon can be stored in the soil before it reaches saturation point.

Although there is still some research to be done, these gardens are cheap, multifunctional and will reduce the amount of carbon dioxide in our atmosphere as part of the fight against climate change. Look out for sites springing up around the UK – the team have already set up other gardens in County Durham and North Lincolnshire.