Research by Cambridge University investigated the technical potential for land in the UK to be spared from food production and returned to woodland or wetland, and the potential for this to mitigate GHG emissions. The study considers the scenario where if yields rise the area of farmland required for food production can decline – allowing countryside to be spared. By converting spared land back to natural habitats of woodland and wetland a large carbon sink is created, sucking in and storing carbon.
The study convened leading experts from ADAS, the Royal Society for the Protection of Birds, Forestry Commission, Rothamsted Research, Scotland’s Rural College (SRUC) and the Universities of California, Bangor, Aberdeen and East Anglia to assess the technical potential to improve productivity of crops and livestock in the UK through improved farm management and breeding programmes to produce plants that are better at capturing soil nutrients, sunlight and water, and to produce more efficient animals that produce less methane. A range of feasible scenarios for long term yield projections were modelled and researchers calculated how much farmland could theoretically be returned to nature whilst fulfilling future UK food demands under a range of scenarios. The GHG impacts of increasing yields and creating woodlands and wetlands were then calculated.
The results suggest that a combination of improved yields and reduced meat consumption could free up enough land to increase forest cover from 12% to 30% of UK land over the next 35 years – close to that of France and Germany, but still less than the European average – and restore 700,000 hectares of wet peatland. These habitats would act as a carbon ‘sink’ capturing enough carbon to meet government targets of 80% greenhouse gas reduction by 2050 for the farming industry. Agriculture currently produces around 10% of all the UK’s damaging greenhouse gas emissions.
The new woodlands and wetlands would be more than just a carbon sink, helping to support declining UK wildlife – including many species of conservation concern – providing more areas for nature recreation, and helping to reduce flooding.
Senior author Prof Andrew Balmford, from Cambridge University’s Department of Zoology commented “Land is a source of greenhouse gases if it is used to farm fertiliser-hungry crops or methane-producing cattle, or it can be a sink for greenhouse gases – through sequestration. If we increase woodland and wetland, those lands will be storing carbon in trees, photosynthesising it in reeds, and shunting it down into soils.”
“We estimate that by actively increasing farm yields, the UK can reduce the amount of land that is a source of greenhouse gases, increase the ‘sink’, and sequester enough carbon to hit national emission reduction targets for the agriculture industry by 2050,” he said.
“We need to turn our minds to figuring out policy mechanisms that can deliver sustainable high yield farming that doesn’t come at the expense of animal welfare, soil and water quality, as well as safeguarding and restoring habitats. If we are serious about saving the planet for anything more than food production then the focus has to be on increasing yields and sparing land for the climate. We need to look objectively and dispassionately at every option we have for achieving that” Prof Balmford added.
Dr Daniel Kindred, co-author from ADAS said “This study shows the importance of yield improvement in making crucial decisions on land-use possible. Whether we can afford to return productive land to nature in the future remains to be seen, but without large increases in productivity to meet rising global food demands there will be no option to spare land and claim the benefits highlighted here. If we are to achieve the ambitious upper yield projections used here action is required now to encourage innovations to break the yield plateau we’ve had for the past twenty years. This is why initiatives like ADAS’ Yield Enhancement Network (www.yen.adas.co.uk) are so important.”
This study, published this week in the prestigious journal Nature Climate Change, is the first to show that land sparing has the technical potential to significantly reduce greenhouse gas emissions at a national scale. It has been widely reported including on the BBC website and on Farming Today.