A more evidence-based approach to land use policy is urgently needed to meet climate and biodiversity goals while maintaining domestic food production and avoiding the export of environmental harm to more vulnerable regions of the world. We must also embrace the technologies and innovations which can deliver low-impact increases in agricultural productivity, argues Professor Ian Bateman, land use economist at the University of Exeter.

 

Across the UK, we face an extensive and growing set of land-related environmental targets - spanning climate change mitigation, biodiversity recovery, water quality improvement, flood risk reduction, and more. These goals are not optional. If we genuinely want a sustainable agricultural sector in the decades ahead, we must treat these targets as non-negotiable. They reflect real environmental limits and respond to genuine ecological degradation.

 

However, we must also confront the consequences of how we choose to meet these goals - particularly the consequences for land use and for the nation’s food production. These environmental targets directly impact the amount of agricultural land available, and therefore the amount of food we produce. Understanding these interactions is essential.

 

Land use, food output and leakage

When the UK redirects land from agriculture to environmental uses, two things happen. First, agricultural production is affected, and different regions experience different economic and land-use impacts. Second, and just as importantly, total food output is likely to fall unless we counteract those losses through increased productivity.

 

A decline in domestic agricultural production has global consequences. Demand for food does not simply disappear because we have chosen to use more of our land for nature. Unless we increase production elsewhere in the UK then we will increase imports. That means the food we no longer produce here will be produced somewhere else - often in regions where costs are lower because environmental safeguards are weaker, where impacts on fragile ecosystems are permitted or carbon emissions are higher per unit of food produced.

 

Carbon, of course, is wholly indifferent to national borders. A tonne of carbon emitted in the UK is identical in effect to a tonne emitted in the Amazon or Southeast Asia. If our well-intentioned domestic policies merely displace emissions abroad - reducing them here while raising them elsewhere - we risk exporting environmental harm to more vulnerable regions of the world.

 

This ‘leakage’ effect is not limited to carbon. Biodiversity loss can also be exported. If we protect nature here only by putting additional pressure on habitats elsewhere, the outcome for biodiversity at a global level may be worse. That is why decisions about land use cannot be made in isolation - they must be evaluated for their full, system-wide effects.

 

The limits of incremental approaches

Current UK agricultural policy is focused primarily on what is often erroneously termed ‘nature-friendly farming’: small, scattered interventions such as field margins or isolated patches of protected habitat. While these initiatives can deliver benefits, particularly for common species, they do relatively little for the species most at risk, which tend to require larger, better-connected non-agricultural habitats.

 

What’s more, the cumulative effect of carving out these small areas of land, alongside the promotion of lower-yield farming practices, is a measurable reduction in food output. More land diverted from farming without compensatory productivity gains means more imports - and therefore greater environmental impacts elsewhere.

 

A more radical approach – rewilding – has attracted both criticism and support. Larger, connected conservation areas can indeed provide the kind of habitats that threatened species genuinely need, and given the UK’s depleted state of wildlife overall, rewilding deserves serious consideration. Yet without parallel increases in agricultural productivity, large-scale rewilding would also significantly reduce food output, again shifting environmental costs overseas.

 

Organic farming presents a similar challenge. While often promoted as a solution, organic systems generally produce substantially lower yields. Lower yields translate into larger land footprints, and therefore greater reliance on imports. Furthermore, organic methods do not necessarily provide the specialised non-farmed habitats that many at-risk species require.

 

Towards a smarter, more integrated approach

A crucial insight is that simply expanding the number of small conservation areas is far less effective than rationalising and enlarging them. Aggregating fragmented patches into larger, ecologically meaningful units would provide much greater benefit for priority species. That alone would be a relatively low-cost improvement.

 

But the most effective strategy combines two actions:

 

1. Increasing the quantity and quality of conservation land in the areas most valuable to at-risk species, and

2. Simultaneously increasing high-yield, low-impact food production elsewhere, ensuring the overall food supply is maintained or enhanced.

 

This dual approach allows us to expand critical habitats while avoiding reductions in domestic food production - and thus reducing the environmental footprint of imports.

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Choosing the right places for the right uses

The first step in achieving this balance is to assess the full impacts of policy changes. Farming and land use policy decisions are often made without proper impact assessments, or with a focus only on intended domestic effects while ignoring international spillover. Leakage - whether of carbon or biodiversity - must be explicitly assessed and accounted for.

 

The second step is to adopt a more strategic ‘right thing in the right place’ approach. Consider tree-planting as an example. The UK must plant substantial numbers of trees to meet its net-zero commitments. But a flat-rate subsidy paid uniformly across all land ignores the reality that land can vary enormously both in terms of foregone food production (its ‘opportunity cost’) and its environmental potential. Planting trees in low-yielding upland areas may minimise food production losses, but these are also the places where trees grow least effectively, capturing very little carbon per pound spent. When assessed properly, such schemes can end up offering poor value for money.

 

The natural capital approach set out in Treasury guidance already offers a better method. This framework evaluates not only the cost of subsidies and the anticipated change in agricultural output, but also the carbon sequestration benefits, water-quality effects, biodiversity implications, and other environmental impacts that land use change generates. Many of these can be robustly quantified; for those that cannot - particularly biodiversity - rule-based requirements such as biodiversity net gain can be applied. When we take this more comprehensive approach, the optimal areas for investment in environmental schemes often look very different to those which flat-rate subsidies encourage.

 

Crucially, we must also avoid relying on outdated agricultural land classifications (ALC) . The ALC system no longer reflects the crop yields that have evolved with modern farming systems and technological advances, and relying on those classifications could risk sacrificing more food output than anticipated.

 

We already have, in the UK, a suite of tools that can guide more precise, evidence-based land-use decisions. They have been developed over the past 10 years and should now be used systematically as the government progresses plans for a farming roadmap, land use framework and national food strategy.

 

Investing in productivity

Finally, none of this will work unless we significantly raise agricultural productivity. This is essential if we want to free-up land for environmental restoration without reducing or displacing food output. Doing so not only enables habitat expansion here in the UK, but also reduces the pressure we place on ecosystems abroad by lowering our import needs.

 

Gradual, incremental changes will not be enough. To meet our non-negotiable environmental targets while maintaining domestic food production and avoiding the export of ecological harm, we must urgently develop a more evidence-based approach to land use policy. We must also embrace the agricultural technologies and innovations needed to deliver low-impact increases in productivity. Sustainable yield improvement is the keystone that will enable us to deliver the environmental improvements and food security that future generations need.

 

Professor Ian Bateman is Director of the Land, Environment, Economics and Policy Institute (LEEP) at the University of Exeter, UK. His main research interests revolve around the issue of ensuring sustainable wellbeing through the integration of natural and physical science with economics and by working with business and policy makers. Ian has been advisor on environmental improvement to senior Government Cabinet ministers for over a decade, advises the First Minister of Scotland, and was a member of the Natural Capital Committee, various HM Treasury working groups, and the Board of the UK Joint Nature Conservation Committee.