Beaver reintroduction is an example of a programme that could blossom after Brexit. Credit: Mike Symes/Devon Wildlife Trust

Britain’s environment faces significant risks from Brexit, with protections for wildlife and millions of euros in funding for environmental programmes now facing an uncertain future. But the pending departure of the United Kingdom from the European Union will free lawmakers to craft UK-specific legislation — and some environmental researchers spot a rare chance to use their expertise to shape future policy.

“The decision to leave the European Union presents substantial risks, but also significant opportunities,” says Sue Hartley, an ecologist at the University of York, UK, and president of the British Ecological Society. She gave evidence to a parliamentary inquiry into the impact of Brexit on the environment, which was led by Member of Parliament Mary Creagh and released its conclusions on 4 January.

The process of leaving the EU is due to start by the end of March 2017, and must be completed within two years. To avoid a sudden change in how things work, the UK government says it will introduce a ‘great repeal bill’ that will largely convert EU laws into UK ones. But it will then be able to modify or strike out EU laws, something that currently requires unwieldy negotiations with the rest of the EU.

Some environmental campaigners are worried about what this will mean for the EU legislation that currently safeguards UK birds and habitats. “The evidence has shown that these directives are effective,” says Martin Harper, conservation director of the Royal Society for the Protection of Birds. Creagh’s committee has called for an act to safeguard existing protections for UK wildlife ahead of the implementation of the great repeal bill.

But environmental researchers, many of whom have spent years pushing for reforms to huge EU programmes only to be frustrated by the slow pace of change, also spy an opportunity — in particular when it comes to one of the most contentious pieces of EU legislation, the Common Agricultural Policy, or CAP.

In the United Kingdom, most CAP funding is spent on direct payments to farmers to support their income. This amounts to around £1.8 billion (US$2.2 billion) annually. A smaller proportion — £400 million — goes to programmes that benefit the environment, such as paying for buffer strips between fields to promote wildlife habitat or to reduce damage from fertilizers.

But scientists argue that more of the CAP money should go towards environmental protection. Reforms in 2013 were meant to make CAP greener, such as a rule requiring farmers to grow at least three crops to maintain biodiversity, but this did not assuage all concerns. “It’s pretty hard to make the Common Agricultural Policy worse than it currently is,” says Dieter Helm, an economist at the University of Oxford.

In September, Helm wrote a report exploring ways in which a post-Brexit United Kingdom might replace CAP. His preferred option is a radical overhaul that would eliminate automatic subsidies to farmers. Instead, the government could target investment at rural programmes that provide proven benefits, such as reducing pollution or increasing biodiversity, he suggests. These could involve payments to farmers who modify their farms to provide such green benefits.

Richard Brazier, who studies the environmental impact of land use and agriculture at the University of Exeter and was a witness in the parliamentary inquiry, also spots an opportunity to reform CAP. His specialism is landscape restoration, in which farmed land is altered to provide better ‘ecosystem services’ alongside food production. One example is reintroducing beavers to benefit flood management. A UK-specific agriculture policy could aim to rewild between 1% and 10% of farmed land, he suggests.

He recommends that any new policy removes existing barriers to rewilding, such as CAP rules that effectively penalize farmers for transforming woodland or ponds into wildlife habitat that does not produce crops. The parliamentary report also mentions the possibility that rewilding, and the removal of these disincentives, could feature more prominently in UK-only laws.

But there are risks associated with losing CAP. The government has guaranteed to fund existing CAP payments until 2020, but on 4 January, environment minister Andrea Leadsom pledged to “design a domestic successor to CAP” while scrapping various pieces of EU legislation — including the three-crop rule — and “cutting the red tape that comes out of Brussels”.

Even researchers who have criticized CAP in the past fear that modifications could undermine its environmental benefits. Lynn Dicks, an applied ecologist at the University of East Anglia in Norwich, co-authored a highly cited critique of the 2013 reforms (G. Pe’er et al. Science 344,1090–1092; 2014), but in 2013 she also reported that many schemes designed to protect wildlife produced consistent benefits (L. V. Dicks et al. Conserv. Lett. 7,119–125; 2014). “I think we’ve been quite innovative actually, within the CAP,” she says. “It’s terrifying to me that we might lose all of it.”