Ten years on from the Brexit vote: Assessing the impact on UK environmental law for the American Bar Association Section of Environment, Energy, and Resources

By Simon Tilling

6 May 2026 8 min read

Trends | May/June 2026

This article was written for the ABA Section of Environment, Energy, and Resources by Simon Tilling, Partner, Burges Salmon, and Ben Stansfield, Partner, Gowling WLG. Simon and Ben are the joint co-convenors of the UKELA International Group.

Ten years on from the Brexit vote: Assessing the impact on UK environmental law

Those of you who made the 48th Spring Conference in Denver in March 2019 were forced to endure two downbeat Brits bemoaning the state of our once glorious nation. However, those listening carefully to our content (and not just to our whinging tone) will have heard that there were opportunities as well as risks, and our central message was that much depended on the extent of the UK’s environmental ambitions once environmental policy and law came firmly back in its own hands. We made some predictions, talked about the headwinds, and speculated about what #greenbrexit means, but in 2019 (and though it pains us to admit it) we just didn’t know what would happen.

Ten years on from the Brexit vote in June 2016, and more than half a decade on from the UK’s departure in January 2020 (and its exit from the single market and customs union at the end of that year), we have got back together to ask: Were we right? Did our predictions come true? Do our magical fortune telling powers deserve a residency in Las Vegas?

The EU as a single market: The REACH chemicals regulation

Our crystal ball said…

We used the regulation of chemicals as the prime example of the practical difficulties of Brexit. The idea of two separate Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regimes, duplicating the significant costs and creating non-tariff barriers to trade, was no one’s idea of an opportunity. Unusually, there was almost no one who could point to silver linings on this cloud: industry, environmental non-governmental organizations, and Prime Minister Theresa May had all wanted “associate membership” of the European Chemicals Agency to keep as much stability as possible (the EU refused on the grounds this is “cakeism”). Of course, there were those who argued that the UK could scrap REACH altogether, but that was never on the cards: it was clear that whatever trade deal was struck between the EU and the UK, there would need to be close alignment on standards. We predicted that the UK would not have the appetite, or resources, or capabilities to fully replicate EU REACH and whatever was put in place would end up riding on the coattails of its bigger European brother.

...and were we right?

Entirely. The UK does have its own REACH regime on paper, but it is a low-fat (or lite) version of the EU regime. The central concept of REACH is that those manufacturing or importing substances should provide a dossier of scientific data about the substance in a central registry for the authorities to evaluate, but the UK’s registry is almost entirely empty. Obtaining data rights to submit to the database was one of the main costs of replicating the REACH regime and it is no surprise that the original deadlines for the submissions of dossiers in 2023, 2025, and 2027 have been postponed not just once (to 2026, 2028, and 2030) but twice: the UK has this year extended the deadlines to October 27, 2029, October 27, 2030, and October 27, 2031. As well as pushing back the deadline, the UK is intending to introduce a new, lower-cost registration model known as the Alternative Transitional Registration model (ATRm), and the extension of time is needed to work out the details of what that model with be.

REACH is not just about a full database: the purpose of the data is to enable authorities to take regulatory management decisions (most notably, restrictions on the substance, or requiring authorization for use) including bringing items forward to the candidate list of substances of very high concern (SVHCs). You won’t be surprised to hear that the UK has lagged far behind the EU on all three metrics. Most tellingly, upon exit the UK set its own “interim principles” for deciding whether to add SVHCs to the candidate list, and then failed to add any. This year it scrapped those interim principles and decided instead to––wait for it––copy the EU list “where appropriate.” Riding on the coattails, indeed.

The EU as a player on the global stage: The EU Emissions Trading System (ETS)

Our crystal ball said...

We highlighted the delicious irony that the EU ETS was in fact modeled on its UK-only precursor, and noted that unlike REACH, the EU ETS was less about protecting the single market and more about global climate leadership. Whatever form Brexit took, the UK would need a replacement carbon pricing mechanism: the withdrawal agreement committed the UK to “a system of carbon pricing of at least the same effectiveness and scope” as EU ETS, whilst a no-deal scenario would see a temporary carbon tax of £16 per tonne as a stopgap. We mused that a revised UK ETS could eventually link back to the EU system, much as the Swiss were attempting, but the glacial pace of the Swiss project rather made our point about how straightforward that would not be.

...and were we right?

Largely, yes. The UK launched its own emissions trading scheme on January 1, 2021, the very day after the transition period ended––because nothing says “Happy New Year” quite like a new carbon market. The £16 per tonne no-deal carbon tax was mercifully never needed. The UK ETS initially mirrored the EU system closely but set its cap 5 percent below the UK’s notional share of the EU ETS cap––a modest statement of intent. Since then, the UK has progressively tightened that cap to align with its net zero by 2050 target and extended the scheme’s reach to cover domestic maritime emissions. So far, so ambitious. The less rosy picture is on price: UK carbon prices have generally traded below their EU equivalents (at times, significantly so), raising questions about whether the UK system is driving the same level of decarbonisation investment. Free allowances to industry are being phased down, but the UK has been slower than the EU to introduce a Carbon Border Adjustment Mechanism (CBAM)––the EU’s CBAM began its transitional phase in October 2023, whilst the UK’s equivalent remains a work in progress. As for linking back to the EU ETS? We hate to say we told you so, but the Swiss finally linked their system in 2020 after 10 years of negotiations. The UK has not even formally begun the process.

The EU’s role in setting common goals: The habitats and birds directives

Our crystal ball said...

We observed that the EU’s biodiversity and habitats regime was one of its great success stories, with over 18 percent of EU territory designated as protected––and that the UK had built its own complex tapestry of protections for everything from cold water coral reefs to mountain summits. In 2019, no one had the political appetite (or, frankly, the time) to start unpicking those protections. Our concern, though, was that future governments might be tempted to take a machete to what they could characterize as “European red tape,” with habitats and species––being somewhat lacking in the ability to lobby––making for easy and voiceless targets. The emerging concept of mandatory habitat offsetting, we noted, was either an encouraging development or a convenient mechanism for fast-tracking damaging development, depending entirely on one’s level of optimism.

...and were we right?

On balance, our cautious optimism was warranted––just. The good news first: the complex tapestry of habitat and species protections survived Brexit largely intact. The Habitats Regulations were “retained” in domestic law and continue to underpin the UK’s network of protected sites. The real scare came in 2023, when the Retained EU Law (Revocation and Reform) Act threatened to “sunset”––that is, automatically repeal––all retained EU law by the end of that year. We held our breath, but the government blinked: the mass sunset was abandoned and replaced with a far more targeted list of provisions to be revoked. The habitats regime survived, but with a pro-growth government ambitious to build 1.5 million homes and 150 infrastructure projects, the great crested newts don’t feel entirely comfortable.

On the offsetting question, we can claim some prescience. Mandatory biodiversity net gain (BNG)––requiring developers to deliver a minimum 10 percent net gain in biodiversity––became law in England in February 2024, with small sites following in April and large infrastructure projects following in May this year. Our experience so far is positive––some sites are proving too difficult to develop (due to the cost of offsetting) and many developers are embracing their inner-ecologists. At the end of 2025, the Planning and Infrastructure Act received Royal Assent and created a framework for nature restoration levies to be applied, enabling developments to adversely impact certain habitats or species in return for a payment into a pooled fund to be applied to mitigation measures. The government is due to publish the detail during the course of the year and we delivering large-scale recovery. In the meantime, the great crested newt’s anxiety is rising.

The EU’s role as enforcer of environmental standards: The Office for Environmental Protection

Our crystal ball said...

By the Spring of 2019, the government had already proposed a new “oversight” body to ensure the UK government was held to account for meeting environmental legal obligations, so we can claim no clairvoyant powers for predicting that the new Office for Environment Protection (OEP) had a critical role as the replacement for the European Commission’s enforcement function. We were quite excited about the concept, but we questioned whether the OEP would be willing to use its sharp enforcement “teeth.”

...and were we right?

For once, maybe our British pessimism was not justified. Despite modest finances, the OEP has punched above its weight, making strategic interventions in court cases, issuing timely reports to influence the legislative process, launching investigations into the government and its regulators, and making findings that the government has been in breach of environmental law. The OEP might not have the resources of the European Commission, but it is certainly playing its role in post-Brexit environmental governance. The issue for the OEP will be resources: last year the chief executive told a parliamentary committee in Westminster that the OEP was never funded to the level that it should have been, and its activities were constrained by its headcount. With the future economic outlook in the UK less than rosy, the OEP is unlikely to get the funds needed to fulfil its full potential.

Our conclusion? Maybe there are times when you don’t want to be proven right...

...the evolution, challenges, limitations, and successes of the UK’s independent environmental law landscape outside of the EU Single Market...

https://www.americanbar.org/groups/environment_energy_resources/resources/trends/2026-may-june/