Biology Letters has just published a mini-series on “Enhanced rock weathering: biological climate change mitigation with co-benefits for food security”.
Tell us about yourself and your research
I am the Director of the Leverhulme Centre for Climate Change Mitigation, based in the Department of Animal and Plant Sciences, at the University of Sheffield.
The challenge facing the Centre is harnessing world-class expertise to objectively investigate enhanced rock weathering with croplands as a strategy for safely removing the greenhouse gas CO2 from the atmosphere to cool the planet.
Amending soils of managed croplands with crushed reactive silicate rocks accelerates their chemical breakdown, pulling CO2 from the air into soils and, eventually, the oceans. These processes also release nutrients that fertilize crop growth and protect against crop pathogens, potentially lowering fertilizer and pesticide usage and costs.
Our long-term programme of multi-disciplinary research is organized across four themes: Earth Systems Modelling, Fundamental Science, Applied Science and Sustainability & Society. It aims to deliver transformative understanding of enhanced weathering with agriculture as a strategic ‘negative emissions technology’ for climate change mitigation, with the co-benefit of delivering resource-efficient sustainable food security.
What made you commission this mini-series in Biology Letters?
In the light of the Paris Agreement and recent political events in the USA, there is an urgent need to develop research strategies for understanding how we might remove the CO2 from the atmosphere to avert future climate change.
Several different options are on the table but those typically highlighted in political circles are, as yet, prohibitively expensive, and it is uncertain how effective they might be. This will also require unimaginable investment in developing large-scale infrastructure and involve potential land use conflicts (food vs. bioenergy), and huge demands for water that threaten food security. Additionally, and as with all atmospheric CO2 removal options, there are substantial issues of public trust.
The papers in the mini-series highlight the potential of enhanced rock weathering as a strategy for offsetting fossil fuel emissions by adjusting current management practices of croplands. I wanted to bring together a set of experts (mostly associated with our Centre) to explain the science at the core of this exciting, potential win-win, option for tackling climate change — capturing CO2 whilst improving croplands to reduce fertilizer and pesticide inputs and costs.
What are the main points readers should take from the articles?
The underpinning science gives us cautious optimism that cropland management could be radically transformed within a decade or two, delivering new ways of thinking about carbon capture and storage that helps address the dual threats to society of climate change and food security. But the next steps are developing the science further to establish a solid evidence base for a wide variety of croplands, soils and climates.
Did you learn anything new from the articles?
Nick Pidgeon and Elspeth Spence’s article provided encouraging provisional evidence that the UK public is likely to be supportive of research into enhanced weathering. It is not as controversial as, for example, geoengineering schemes that fall into the category of solar radiation management. In such schemes, for instance, particles are injected into the stratosphere to block sunlight from reaching the Earth’s surface. These scheme might work fast and could be relatively cheap but they don’t address the root cause of global warming – high levels of greenhouse gases, especially atmospheric CO2. So we are sentencing future generations to continue to manage the incoming solar radiation for hundreds of years whilst we simultaneously figure out ways of removing CO2 from the atmosphere and reducing emissions. There has to be a better way.
CO2 removal as discussed in the mini-series, on the other hand, is relatively expensive and time-consuming but it helps solves the problem. There is no magic bullet to solving the climate change problem. Addressing it requires a portfolio of options.
