The government pledged that leaving the European Union (EU) would lead to a greener UK, with more robust environmental policies and protections being introduced.
But in practice, the government has actually kept a lot of EU law in place after Brexit. In fact, around 80% of the UK's environmental laws still come from the EU, according to the government's Future of the Natural Environment after the EU Referendum report.
But the government has made some changes. It introduced the Environment Act in 2021, which created a new legal framework for environmental protection. It has also set new targets to reduce emissions in its Net Zero Strategy.
Because most of these changes have only happened in the past two years - and some adjustments are still being made - we can't really measure the real-world impact of Brexit on the environment yet.
What we can do is look at how environmental policy has changed, and what the consequences could be for the future of the environment in the UK.
What has been the environmental impact of Brexit?
So far, Brexit hasn't had much of a positive or negative real-world impact on the environment. Most new UK environmental policies were only created in the past two years, and many are still being decided and refined.
In fact, less than three years have gone by since Brexit was made official. Although the UK public voted for it in 2016, the country didn't actually leave the EU until the 31st of December 2020.
But how has the government done in such a short space of time? Greener UK - a coalition of leading environmental groups - says that so far, the government has failed to deliver on its "promised 'Green Brexit'.
Most key areas of environmental concern, such as water and air quality, waste management, biodiversity, and agricultural practices, are more or less in the same state as they were before the UK left the EU.
While some areas of environmental concern have gone pretty much unscathed, other areas, such as chemical regulation, and air quality standards are arguably worse off after Brexit.
However, there have been minor legislative improvements in some industries such as fishing and farming, which could them more sustainable.
Negative environmental impacts of Brexit
One of the major downsides to Brexit is that it has weakened legal protections around the environment. Key environmental protection areas, such as chemical regulations, air quality, waste management, and nature conservation, are worse off after Brexit, according to Greener UK's Risk Tracker.
But how exactly has Brexit impacted these areas of concern? Let's take a closer look.
The UK's clean air targets are not ambitious enough
Since the COVID-19 lockdowns happened at the same time Brexit kicked off, it's difficult to assess whether Brexit has led to a reduction in air pollution levels in the UK, or whether it's been down to altered behaviour after COVID.
What we do know is that the recent air pollution targets the government set out in its 2023 Environmental Improvement Plan are far less ambitious than the ones set by the EU.
The UK is aiming to reach an annual target of emitting 10 micrograms per cubic metre of fine particulate matter - harmful air pollutants - by 2040. Current annual emissions are around 12.9 micrograms per cubic metre for particulate matter, and 15.8 for nitrogen dioxide, another harmful air pollutant.
The EU, which published its objective several months before the UK, has promised to achieve that same target ten years earlier, by 2030.
The UK's new frameworks for road development also ignore the negative environmental impacts of traffic emissions, and focus on introducing a major road-building spree. These plans are likely to hinder the government's plans to hit its clean air targets.
The new UK chemical regulation system is a mess
After Brexit, the UK created its own chemical regulation system called UK REACH, which has been criticised by many industry experts and green advocates for being weaker than the EU REACH system it replaced.
The main downside to UK REACH? It offers fewer protections against the misuse of harmful chemicals. Its list of "very high concern" and hazardous chemicals also needs to be expanded, since it currently lists fewer chemicals than the EU, according to the Green Alliance.
To address these concerns, the UK government has promised to publish a revised Chemicals Strategy in 2023.
But the main problem with the government's plans is that the transition from one system to the next has created a data gap for chemical registration in the UK.
Michael Warhurst, the executive director of CHEM Trust - a UK and European charity that works to protect people and wildlife from harmful chemicals - has noted his concerns:
"The UK system will not have registration data on the highest volume chemicals for another four years - 15 years after the EU REACH registration deadline for these chemicals."
Meanwhile, the EU published their amended chemicals strategy in 2022, which sets the legal framework for stricter regulations and new environmental protections, such as new classifications for harmful chemicals, and new criteria for what qualifies as "essential use".
Hundreds of environmental laws are at risk of being revoked at the end of 2023
In September 2022, the government put forward the Retained EU Law (REUL) bill. Under this bill, leftover EU laws post-Brexit would be automatically removed after the 31st of December 2023 - unless the government actively chooses to keep them.
As it stands, most of the laws put in place in the UK that ensure environmental targets are met are retained EU laws. Many environmentalists are worried that the REUL bill will remove legal protections around the environment.
Regulations on species and habitat protection, air pollution limits, and food and water safety laws, to name a few, could be scrapped, according to Client Earth.
Positive environmental impacts of Brexit
There haven't been many positive environmental impacts from Brexit, despite the government's promises. However, there have been a few improvements made to farming and fishing policy, according to Greener UK.
But what are the implications of these changes?
There are new incentives to encourage environmentally friendly farming
After leaving the EU, the UK government published the Environmental Land Management Scheme (ELMS), which included the Sustainable Farming Incentive scheme.
The initiative encourages farmers to adopt sustainable practices by paying them to provide "public goods." These include improving water quality and biodiversity, mitigating climate change, and improving animal welfare.
Farmers can be paid for maintaining flower rich grass to help with biodiversity, or for creating buffer strips at the end of their fields to help protect wildlife.
But ELMS is far from perfect. There have already been delays in payments to farmers, and many didn't sign up for the scheme because the subsidies were initially too low.
The government made some improvements to the scheme in January 2023. But non-profit organisation Friends of the Earth says that payment incentives are still too low.
The current new payment includes an extra £1,000 per year for participation, in addition to the payments for maintaining sustainable standards. This is intended to help cover the cost of participation.
But given the difficulties farmers are already facing with increased operational costs due to the energy crisis, this may not be enough.
The EU is also trying to reform its Common Agricultural Policy (CAP) - the scheme that ELMS replaced. The policy has been criticised for encouraging unsustainable practices, prioritising economic competitiveness, and not giving farmers enough incentives to 'go green', according to the European Agricultural Agency.
However, the reform process is happening slower than planned, after various EU members challenged the proposed CAP changes.
It's easier to change fishing policies to make them more sustainable
In 2020, the UK government passed the Fisheries Act to replace the EU Common Fisheries Policy (CFP).
This new legislation offers more flexibility. It makes it easier for each devolved nation to change fishing quotas and regulations, in response to decreasing fish populations and biodiversity decline.
The EU Common Fishing Policy (CPL), on the other hand, has been criticised by experts in the industry, because it sets fixed quotas for fishermen, which apply to all member nations - regardless of their location. This makes it difficult to adapt quotas to reflect changing levels of fish populations.
The UK Fisheries Act sets out new sustainability objectives for fisheries, but doesn't specify quotas or policies. These are handled separately by each devolved nation across the UK.
In theory, this means that under the UK fishing regulatory system, fishing quotas are easier to change than they were under EU law.
However, the UK government has also been criticised for not setting out rules against overfishing, and for breaking its own laws on sustainable fishing.
Many of the fishing quotas it has set since creating the Fisheries Act are 65% higher than the level scientific advisors have said is sustainable. This figure suggests that the UK's new fishing legislation could actually be doing more harm than good to the environment.
How does the UK's carbon footprint compare to EU countries?
The UK's carbon footprint is relatively similar to other large European countries.
In 2021, the UK's greenhouse gas emissions per person was 6.2 tonnes. It also accounted for roughly 1% of the world's carbon dioxide equivalent (CO2e) emissions in 2021, which mostly came from burning fossil fuels, such as coal, oil, and gas.
To get an accurate comparison, it's best to compare two countries' greenhouse gas emissions per person, instead of for a country as a whole. This is because countries with larger populations tend to produce more emissions overall.
Germany, for example, produces more CO2e than the UK, which isn't surprising, since it has a larger population. But Germany also produces more greenhouse gases per person compared to the UK - with a total of 8.9 tonnes of greenhouse gases per person in 2021.
France - another large European country - produced fewer greenhouse gases per person in 2021, compared to both the UK and Germany - around 6 tonnes per person.
And Sweden produced a similar amount of greenhouse gases as the UK, with an average of around 6.2 tonnes per person.
The UK isn't the worst offender in Europe when it comes to greenhouse gas emissions. If anything, what these figures show is that all major European countries need to be doing more to reduce their emissions.
Summary
The UK government has made some changes post-Brexit that can make farming and fishing practices more sustainable, in theory. In practice, for fishing, experts believe that this new legislation is still leading to yields that are 65% more than the sustainable rate.
And, many issues that existed before Brexit, such as poor water quality and waste management, high air pollution, and biodiversity loss, have not improved since the UK left the EU - and in some cases, have gotten worse.
And even though the government has set out ambitious targets in its 2021 Environmental Act and Net Zero Strategy, it's not on track to meet them.
In fact, in 2022, the High Court ruled that the government had not given enough detail on how it would meet its net zero targets. In response, the government has since published a new plan, Powering Up Britain.
Brexit gives the UK government the chance to make new policies to better protect the environment. But so far, the government hasn't taken advantage of this opportunity.
