Research published recently in the journal Science by a team of conservation scientists and economists suggests that conservation efforts in industrialised nations risk shifting harmful land use to other, less developed and more biodiverse parts of the world. From a UK perspective, domestic farm policies which take farmland out of production, or which encourage the adoption of lower-yielding practices, must take account of the wider biodiversity impacts of displaced or reduced food production. To avoid impacts which could be up to five times more damaging in other parts of the world, and working alongside demand-side interventions such as dietary shifts and waste reduction, it is vital that our farmers have the necessary tools and incentives to make up the shortfall here, by closing the yield gap and increasing production on remaining farmland, argues one of the study’s co-authors, conservation scientist Professor Andrew Balmford FRS.     

 

Efforts to preserve or rewild natural habitats in industrialised nations risk shifting harmful land use to other, less developed parts of the world – and this could drive an even steeper decline in the planet’s species.

 

That is the worrying conclusion of a recent paper I co-authored with a team of conservation scientists and economists, led by the University of Cambridge, and published in the journal Science.

 

Together, we warn that ringfencing certain areas for protection or restoration can lead to the displacement of nature-damaging human activities to other areas of importance for nature. The paper’s 22 co-authors have called on the international community to recognise and start working to tackle this “biodiversity leak”.

 

In particular, we argue that rewilding productive farmland or forestry in more developed nations that have low levels of biodiversity risks doing more harm than good on a planetary scale, and that these impacts must be understood, accounted for and mitigated in policy-making decisions. 

 

Our analysis suggests, for example, that reclaiming typical UK cropland for nature may be as much as five times more damaging for global biodiversity than the benefit it provides in terms of protecting local species, due to the displacement of food production to more biodiverse regions of the world.   

 

While this “leakage” has been known about for decades, it is largely neglected in biodiversity conservation. Even the UN’s landmark Global Biodiversity Framework – aiming for 30% of the world’s land and seas to be conserved – makes no mention of the leakage problem. As such it undermines the overall contribution of well-intentioned policy actions ranging from establishing new nature reserves to farm-level agri-environment schemes.

 

The simple fact is that as nations in temperate regions such as Europe rewild or conserve more farmland, or adopt lower yielding ‘land-sharing’ agricultural policies, the resulting shortfalls in food and wood production will have to be made up somewhere.

 

Much of this production is likely to be displaced to more biodiverse but often less well-regulated parts of the world, including Africa and South America. Areas of much greater importance for nature are likely to pay the price for conservation efforts in wealthy nations unless we work to fix this leak.

 

A first, important step will be to acknowledge collectively that these leaks exist.

 

‘Leakage’ is already a major issue for carbon credits tied to forest preservation. As one of the paper’s co-authors, Professor Brendan Fisher from the University of Vermont, pointed out: “If protesting a logging concession in the US increases demand for pulp from the tropics, then we are unlikely to be helping biodiversity.”

 

While protected areas can slow deforestation inside their borders, there’s evidence it can simply shift to neighbouring areas. Production can also be displaced much further. Efforts to protect the Pacific Northwest’s old-growth forests resulted in increased logging in other North American regions, for example.

 

Our survey of site managers of tropical conservation projects found that 37% had not come across the concept of leakage, and less than half of the projects were attempting to curb any displacement damage.

 

So, we explored how leakage caused by protected areas could affect global biodiversity by applying real-world food and biodiversity data to two hypothetical conservation projects.

 

Our analysis indicated that rewilding a sizeable area of Brazilian soybean farms would push production to nations such as Argentina and USA, but because Brazil is so important for biodiversity, the local conservation gains could be around five times greater than the displacement harms.

 

The opposite would be true if the equivalent area of UK arable farmland was reclaimed for nature. Here, production would be displaced to Australia, Germany, Italy and Ukraine. As the UK has fewer species than these other countries, damage from ‘leakage’ could be five times greater than the local benefit to British biodiversity. 

 

In the paper we call on governments and the conservation sector to take leakage far more seriously when making environmental policy at national and global level, and suggest a number of ways to help plug the biodiversity leak.

 

One way is to reduce demand in line with local production losses, especially for the most land-hungry commodities such as ruminant meat. There is also scope to limit leakage by targeting conservation to areas high in biodiversity but where current or potential production of food or timber is limited. One example is restoring abandoned tropical shrimp farms to mangroves.

 

But we should also be much more cautious about restoring natural habitats on currently productive farmland in less biodiverse parts of the world, such as the UK.

 

Beyond planning where to conserve, we argue that major conservation initiatives should work with partners in other sectors to help local farmers increase yields on remaining farmland, so that overall levels of food production are maintained in the region despite scaling-up of conservation efforts.

 

Where local yield increases are difficult, larger-scale programmes could establish long-range partnerships with suppliers in the same markets to make up shortfalls in production.

 

So, it is time for policymakers to recognise and fix the biodiversity leak. From a UK perspective, domestic farm policies which take farmland out of production, or which encourage the adoption of lower-yielding practices, must take account of the wider biodiversity impacts of displaced or reduced food production.

 

To avoid impacts which could be up to five times more damaging in other parts of the world, and working alongside demand-side interventions such as dietary shifts and waste reduction, it is vital that our farmers have the necessary tools and incentives to make up the shortfall here, by closing the yield gap and increasing production on remaining farmland.     

 

Andrew Balmford is a Professor of Conservation Science at the University of Cambridge. He has led more than 20 years’ work investigating how to reconcile food production with biodiversity conservation.