Rishi Sunak has given up Britain’s reputation as a world leader in the fight against the climate crisis and has “set us back” by failing to prioritise the issue in the way his predecessors in No 10 did, the government’s green adviser has warned.

Chris Stark, the outgoing head of the Climate Change Committee (CCC), said that the prime minister had “clearly not” championed the issue following a high-profile speech last year in which he made a significant U-turn on the government’s climate commitments. The criticism comes after Sunak was accused of trying to avoid scrutiny of Britain’s climate policies by failing to appoint a new chair of the CCC.

Sunak announced last autumn that he was moving back the ban on the sale of new petrol and diesel cars by five years, as part of a wider dilution of climate policies. At the time, the Tories were aiming to create a dividing line with Labour after their victory in the Uxbridge byelection, which largely came as a result of their opposition to London’s ultra low emission zone.

“It was presented to the country as a step back from going too fast on this transition,” Stark told the BBC. “In the speech itself, he talked a lot about the need to reappraise lots of the steps that take us to net zero. I think it set us back. I think we have moved from a position where we were really at the forefront, pushing ahead as quickly as we could on something that I believe to be fundamental to the UK economy, fundamentally beneficial to the people living in this country, whether you care about the climate or not.”

Stark said significant progress had been made towards net zero and praised Theresa May and Boris Johnson for their commitment to the target. However, he said Sunak had failed to show the same ambition.

“We are now in a position where we’re actually trying to recover ground,” he said. “The diplomatic impact of that has been immense. It doesn’t matter that there were detailed policies within that speech that you could say were very much in line with net zero. The overall message that other parts of the world took from it is that the UK is less ambitious on climate than it once was, and that is extremely hard to recover.”

A government spokesperson said: “We are the first major economy to halve greenhouse gas emissions since 1990 and have set into law one of the most ambitious 2035 climate change targets of any major economy. But we need to reach our net zero goals in a sustainable way.”

Flower farmer John Huiberts stands next to a flamingo made of thousands of organic pink hyacinths. At the annual BloemenCorso, or flower parade, where decorated floats travel through 26 miles of fields in full bloom, his electric vehicle is a sign of changing times in the Netherlands.

“It makes you proud,” said the co-owner of Huiberts Biologische Bloembollen, who went organic 11 years ago. “They say the chemicals are safe but I don’t know. It took me a few years to have good and healthy bulbs, but it is reassuring not to use them any more.”

Huiberts is among a growing number of Dutch flower farmers rejecting pesticides over concerns about conventional floriculture’s effects on biodiversity and the health of people living nearby.

In the past 10 years, Dutch flower farming grew by a fifth, covering 28,000 hectares of Europe’s second most densely populated country. Almost seven billion bulbs were exported in 2022, mostly tulips and lilies, worth about €1bn (£860m).

A court case this week from residents of a village in Limburg aims to stop one lily bulb grower from planting over health concerns about pesticides. Last year, a surprise ruling banned a grower from using pesticides on a Boterveen lily field, citing “substantial evidence” of “a link between pesticides and serious neurological disorders (such as Parkinson’s, Alzheimer’s and ALS)” – although, on appeal, he was allowed to use four substances.

Jonna Vernes is part of a Boterveen group planning to appeal to the courts to regulate future farming. “It is scary,” she said. “From the beginning, we have been concerned about our health.”

Experts have also raised the alarm, in the wake of courtroom victories against pesticide use in the US and state compensation for winegrowers in France who contracted Parkinson’s disease after using glyphosate – a herbicide recently given another 10-year permit for EU use. A critical report from the Noordelijke Rekenkamer audit office said: “It is unclear whether intensive use of pesticides in growing is safe for people, water and nature.”

Prof Bas Bloem, neurologist at the Radboud University Medical Centre, is leading calls for new European testing protocols. “Parkinson’s is the world’s fastest growing neurological condition and there is widespread consensus that it is to a large extent an environmentally driven disease,” he said. “This includes pesticides, although it’s not restricted to pesticides. Farmers have an increased risk, and so do people living in the vicinity of farmland.”

Although total pesticide use has declined since 2012, consumers still expect flowers to look perfect and export standards are high, said Martin van den Berg, emeritus toxicology professor at Utrecht University. “If we compare flower fields like the lilies, the use of pesticides in general is much more extensive than growing corn, wheat or potatoes.

“The more intensively you use the biocides, the larger the impact on biodiversity. And legislation in the EU asks if the compound is carcinogenic or hazardous to reproduction but the one thing which is definitely insufficient is testing on neuro­developmental effects: these compounds are not tested adequately to tell people at a specific dose you’re not at risk – especially children and the foetus in pregnant women.”

Investigative journalists Ton van der Ham and Vincent Harmsen said that when they researched gaps in regulation, they encountered resistance and hostility. “The current laws are not protecting Dutch citizens: a million people live within 250 metres of a field,” said Van der Ham. “We are not against the farmers: we are not activists, we are journalists.

“You could call it tulip fever … the fever that makes us crazy … because we want to make money.”

Back at the flower parade, chairman Willem Heemskerk was keen to point out that the fair – started to cheer people up in 1947 – is a kind of recycling. “Bulb growers allow us onto their fields to gather the flowers,” he said. “This isn’t extravagant use – it is a waste product, and 100 million people will enjoy it.”

Jaap Bond, chairman of the KAVB Royal General Bulb Growers’ Association, said the sector is experimenting with methods such as weed-seeking robots and smart injection techniques. “There is an enormous challenge when it comes to reducing chemical products,” he said. “Everything that is used is a legal chemical that is strictly controlled. This is an enormous, economically important economic sector, but what is often underestimated is that it is also a symbiosis: bulbs are rotated in the ground with potatoes and onions. The lily is really being framed.”

Prof Bloem, however, believes flowers are a “luxury product” and precaution should be prioritised. “Particularly when it comes to flowers, we should ban these pesticides until we have further evidence to show either that they’re toxic or that they’re safe,” he said.

An underwater experiment to restore coral reefs using a combination of “coral IVF” and recordings of fish noises could offer a “beacon of hope” to scientists who fear the fragile ecosystem is on the brink of collapse.

The experiment – a global collaboration between two teams of scientists who developed their innovative coral-saving techniques independently – has the potential to significantly increase the likelihood that coral will repopulate degraded reefs, they claim.

The first use of the combined techniques, to repair damaged atolls in the Maldives, will be shown on the BBC One TV series Our Changing Planet, co-presented by the naturalist Steve Backshall.Hailed as a potential “gamechanger”, the hope is that the technique could be replicated on a large scale to help preserve and revitalise dying reefs.

“All corals in all ocean basins in the world are under pressure,” said Prof Peter Harrison, a coral ecologist at Southern Cross University in Australia.

“Quite a large number have died in some reef areas. So we’re going to end up with big spaces of new real estate for coral larvae, but very few coral larvae being produced because so many adults have died.”

He has pioneered a form of “coral IVF” that involves capturing millions of spawn from “heat-tolerant” reproductive coral after it floats to the sea surface or, alternatively, surrounding coral that has withstood a bleaching event with a cone-shaped net. The net functions like a huge “coral condom”.

“If you breed from heat-tolerant corals that can survive heat stress in the laboratory, the larvae of those corals also have higher heat tolerance than the larvae of other corals,” said Harrison.

The gametes (reproductive cells) then merge together, fertilise and form coral larvae in floating “nursery” pools, which protect them from predators and prevent them from getting lost at sea. “If we don’t support the process of natural selection by focusing on the survivors, we’re going to lose everything.”

This technique, Harrison added, can produce 100 times more coral colonies than would naturally occur on a reef with the same number of larvae: “And we’re working out ways to get it to about 1,000.”

To attract the larvae to settle on a degraded reef, the scientists are broadcasting recordings of fish noises that were captured near a busy, healthy reef. “We’ve done this and restocked degraded reefs with fish,” said Steve Simpson, professor of marine biology and global change at the University of Bristol.

“Working with Peter is the first time we’ve tried it with corals. It maximises the chance that the coral larvae being released find somewhere to live – somewhere that they will then restore the reef habitat.”

Coral larvae, he has discovered, can detect sound according to the way the hairs on their bodies move, and so can be “tricked” into swimming towards – and settling on – a typically silent, unhealthy reef. “It’s like sowing a field that will become a forest again,” said Simpson.

In the lab, the larvae were particularly attracted to the low-frequency grunts, croaks and rumbling sounds made by territorial fish, which can protect coral growing on the reef. “We have discovered that coral larvae hear their way home as babies, before they then choose where to live for up to 1,000 years,” Simpson said.

“They look very simple, and they don’t have ears or a brain, but coral were probably among the earliest animals cueing into their soundscape and dancing to the beat.”

Time is running out for coral reefs across the planet.Scientists recently announced that the world is experiencing its fourth planet-wide coral bleaching event since 1998, with 54% of reef areas in the global oceans experiencing heat stress high enough to turn its colourful coral white. Australia’s Great Barrier Reef has suffered its worst bleaching on record, with about 73% of the 1,429-mile (2,300km) reef affected.

Backshall initially found the idea of using the soundscape of a busy reef to entice the tiny coral larvae to a denuded area “just bananas”.

“To see that happening – to take these gametes into the sea, play them the sounds of a healthy reef and see them actively start swimming towards it – it is probably as close to a eureka moment as I will ever have,” he said.

He fears, however, that if global temperatures rise by 2.5C or 3C, then “coral reefs are doomed”, regardless of these new techniques: “If we continue business as normal in terms of anthropogenic climate change, I don’t think it’s going to matter what we do.

“Tropical reefs are right on the frontline. But if we can keep our levels of temperature increase across the planet down to 1.5C, then there’s a chance – and then these methods will absolutely be part of a positive future.”

The world is “very gradually” waking up to the enormity of the global climate emergency, Harrison said. In the meantime, he and Simpson are “just trying to buy time for corals”.

“If we can keep enough reefs alive through the next two or three bumpy decades to be able to recover, we’ve then got the reefs for the future, once the climate is under control,” Simpson said.

“People say that coral reefs might be the first ecosystem we could lose, and I like to think that, therefore, they are the first ecosystem we can save. If they’re on the brink, and we can save coral reefs, we can save anything. And they become a beacon of hope.”

As we climb the river wall, our steps laboured by the steep bank, the harsh wind suddenly hits us so fast it takes our breath away. The Butley river, with its saltmarsh and mud banks, sweeps ahead on my left. To my right, Boyton Marshes stretches into a bright white horizon. These are the famous Suffolk skies: wide and open.

Continuing on the Suffolk coast path, curlew, Cetti’s warblers and skylarks call. As I look ahead, redshanks busily scour the mud on the river edge. Oystercatchers fly past us, following the river, and a marsh harrier glides above one of the islands in the distance.

We sit just off the path, out of the wind, to drink hot tea from a flask. Signs of spring are everywhere: a dozen black-tailed godwits, each poised on one leg, heads tucked under a wing, their rusty red chests aflame with summer plumage. And flitting above the reeds, three swallows – the first I have seen this year.

As we resume our walk, a spoonbill flies overhead. These spectacular, once scarce birds can now be often spotted on the coasts of East Anglia during the summer months, and some breed elsewhere in the UK. It is a privilege to have them on my doorstep, and it’s amusing how a bird can look slightly comical yet graceful at the same time.

For me this is still trumped, however, by the two small birds that fly across our path in a flash of black, white, gold and amber. They disappear behind dense reeds and bramble. We wait, peeping through our scope, holding our breath – they are the unmistakable bearded tits. Harlequin-like markings on the male, soft buff-coloured faces on the female. Their sleek, streamlined bodies balance between the stems and they move quickly, making their distinctive soft “pinging” call as they work their way along the reeds, appearing for only seconds at a time before diving back into the foliage. Could they be looking to nest? Do they already have a nest? I hope so. So as to not disturb them, we creep away softly.

Later that day, I’m delighted to read that these charismatic birds are not actually a tit; they belong to their own family, the Panuridae. I reflect on this magical spot, and the splendour of knowing that every time I return, I will see something new.

Whistleblowers say UK water companies are knowingly failing to treat legally required amounts of sewage, and that some treatment works are manipulating wastewater systems to divert raw sewage away from the works and into rivers and seas.

It is well known that water companies are dumping large volumes of raw sewage into rivers and seas from storm overflows but an investigation by the Guardian and Watershed Investigations reveals that the industry’s “dirty secret” is bigger, broader and deeply systemic.

By law, every wastewater treatment works must treat a minimum amount of sewage as stipulated in their environmental permits. Four whistleblowers have told Watershed that a large proportion regularly fail to do so and are not reporting it to the environmental regulator.

The insiders say the amount of sewage reaching a works is being “manipulated at the front end” by “flow trimming”, which can be done a number of ways including by “manually setting penstocks to limit the flow”, by “dropping weir levels” and by “tuning down pumps at pumping stations”. The diverted raw sewage makes its way into ditches, rivers and seas.

One industry insider says they “have personally surveyed works and found valves operated and diversion pipes installed so that part of the flow arriving is deliberately diverted to an environmentally sensitive stream, rather than into the works, so that the works passes compliance of sanitary parameters.

“I have spoken to staff who have carried out surveys to inform investment plans, who have found that the controls of terminal pumping stations have been deliberately altered so that they pump only a reduced proportion of the flow figure they were designed to pump, in the knowledge that this was a breach of flow compliance. This continues.”

The insider adds: “I have spoken to [people at] other water companies who confessed that flow compliance is a dirty secret of the UK water industry, which environmental regulators know about (although perhaps not the scale) and have turned a blind eye due to resourcing constraints.”

The raw sewage that is diverted away from the works flows into ditches, rivers and seas and the amount will probably dwarf the volumes dumped into the environment via storm overflows.

“It is an enormous scandal that many who work in the industry know about, but nobody wants to talk about,” said the whistleblower. “Water companies report their overall compliance with wastewater rules as good, but dig a little deeper and you’ll see that lots of treatment works are failing to deal with the amount of sewage they are legally meant to treat.”

The insider says non-compliance is widespread across the UK, and that they are aware of works where as much as 30% of the sewage they are expected to handle goes straight into the environment without treatment.

“Some operators, with or without the support of their chain of command, are deliberately reducing the flow of sewage into the treatment works by either dropping the levels of weirs so that sewage flows out into the environment, or by cutting back the flows at pumping stations. This way they can say they are treating a greater proportion of the sewage they receive because they are now receiving less into the works,” says the whistleblower.

“Sadly there are many incentives for water companies, rogue teams or staff to do this, including reduced cost of pumping and treatment, and treatment works that were struggling to comply appearing to be passing, with the resulting regulatory performance rewards leading to staff bonuses and increased dividends to shareholders – with very little risk that the manipulation will be found or anyone prosecuted.”

A second insider says it is “almost standard practice to control penstocks by hand to set it at a limit to reduce the flow”, adding that the problem “stems from sweating the assets … There are a lot of undersized, overcapacity sewage treatment works out there … and I’ve rarely seen a works where all the assets are working, there’s usually something out of service.

“Spilling to the river saves millions of pounds that they should be spending on assets. Lots of storm tanks are sized to meet 30-year-old permits, and there are sites with no storm capacity at all.”

A third insider says they have seen evidence of flow trimming at works owned by two different water companies.

“Operational teams on site look for a workaround, often in the full knowledge of what they are doing, and in full knowledge of all the stakeholders, from the project manager all the way up to the person holding the purse strings. Other times it’s done without knowing the implications … no one knows the true scale of what’s happening across the country.”

According to a fourth whistleblower, it is possible to identify instances of flow trimming in a company’s figures “but no one truly looks into the data, they won’t look at the detail”.

England’s water companies declined to comment, but the industry body Water UK says: “We recognise the current level of spills is unacceptable and we have a plan to sort it out. Between 2025 and 2030 water companies in England and Wales want to invest £96bn to ensure the security of our water supply in the future and significantly reduce the amount of sewage entering rivers and seas. We now need the regulator Ofwat to give us the green light so we can get on with it.”

Ofwat says water and wastewater companies’ environmental performance is “simply not good enough” and that the industry regulator is “acutely aware of the damage this does to our natural resources and to public trust.

“However, where companies fall short, Ofwat acts – over recent years, we have imposed penalties and payments of over £300m and in November 2021 we announced our biggest ever investigation into all water and wastewater companies in England and Wales, with live enforcement investigations into six companies.

“This is specifically investigating whether companies are treating as much sewage at their wastewater treatment works as they should be, and how this could be resulting in sewage discharges into the environment at times when this should not be happening.”

The Environment Agency is also investigating. A spokesperson says: “We will always pursue and prosecute companies that are deliberately obstructive or misleading, including on issues around flow compliance. We are conducting our largest-ever criminal investigation into potential widespread non-compliance at thousands of sewage treatment works.”

Geraint Weber of the regulator Natural Resources Wales says: “We expect water and sewerage companies to comply with the conditions of their environmental permits. Where non-compliance is identified we won’t hesitate to take action using the full range of enforcement powers available to us.”

Nathan Critchlow-Watton of the Scottish Environment Protection Agency says: “Sepa assess Scottish Water’s compliance with authorisation conditions at wastewater treatment works through site inspections, investigating events and incidents, sampling discharges, assessment of operator data and Sepa’s programme of environmental monitoring. We are not aware of any evidence of deliberate misreporting of overflow data by Scottish Water or other operators.”

A Scottish Water spokesperson says: “We are not routinely required by licence to assess and report whether we are passing the appropriate pass forward flow at our pumping stations and overflows and at wastewater treatment works. We set out to be compliant across all aspects of our licences and are not aware of any instances where we deliberately manage flows to spill early.”

Northern Ireland Water and Welsh Water declined to comment.

Two German-Russian nationals have been arrested in southern Germany on suspicion of plotting sabotage attacks, including on US military facilities, in what officials called a serious effort to undermine military support for Ukraine.

The men, named as Dieter S and Alexander J, are suspected of operating as Russian spies on behalf of the Kremlin, according to German media sources. Prosecutors said only that the men were accused of working for a foreign secret service.

Separately, Polish and Ukrainian prosecutors said on Thursday that a Polish man had been arrested on allegations of spying for Russia in an alleged plot to assassinate Ukraine’s president, Volodymyr Zelenskiy.

The man, identified only as Pawel K, was accused of supplying information to Russian military intelligence about the Rzeszow-Jasionka airport in south-eastern Poland, which is the gateway for international military and humanitarian supplies for Ukraine. Zelenskiy frequently passes through the airport on his trips abroad.

The German prosecutor’s office said the suspects were arrested on Wednesday in the small city of Bayreuth, home to the annual Richard Wagner opera festival. It added that their homes and workplaces were being searched.

According to the statement by prosecutors, the accused were under “strong suspicion” of “having worked for a foreign secret service in a particularly serious incident”.

In addition, Dieter S, 39, was charged with “conspiring to cause an explosive attack and arson, acting as an agent for sabotage purposes and security-endangering collection of intelligence on military installations”.

Dieter S had allegedly been in contact with a member of the Russian secret services and had been developing sabotage plans in Germany since October 2023.

Germany’s foreign minister, Annalena Baerbock, said: “The suspicion that [Vladimir] Putin is recruiting agents from us to carry out attacks on German soil is extremely serious. We will not allow Putin to bring his terror to Germany.”

Baerbock has summoned Russia’s ambassador to Berlin, Sergei Nechayev, for an explanation, a move that happened with unusual haste, suggesting authorities had unequivocal proof of the link between the plot and the Kremlin.

The Kremlin said it knew nothing about the circumstances surrounding the men’s arrests.

According to prosecutors, Dieter S declared his readiness to carry out explosive and arson attacks on military infrastructure and industrial sites, with the explicit intention “to undermine the military support provided by Germany to Ukraine against the Russian war of aggression”.

He focused his attention on German and US military sites, according to the evidence gathered by investigators, which included videos and photographs.

According to Der Spiegel, the US military site Grafenwöhr, in Bavaria, southern Germany, was his main focal point. This is one of the main sites where the US military has been training Ukrainian troops, in particular in the operation of Abrams tanks.

The prosecutors said that based on “underlying facts”, there was a strong suspicion Dieter S had fought in eastern Ukraine between December 2014 and September 2016 for an armed unit of the self-proclaimed republic in Donetsk and had acquired a firearm for this purpose.

The prosecutors described the unit as a pro-Russian association that, “from spring 2014, claimed control over the Ukrainian administrative district of Donetsk with the aim of secession from Ukraine and engaged in intensive clashes with the Ukrainian armed forces. The association repeatedly used violence against the civilian population.”

Alexander J, 37, is suspected of supporting Dieter S from March 2024 at the latest. He is also accused of espionage on behalf of a foreign service.

Dieter S was brought before judges at Germany’s federal court of justice in Karlsruhe on Wednesday and remanded in custody. Alexander J was brought before judges on Thursday, prosecutors confirmed.

Reacting to news of the foiled attacks, Germany’s interior minister, Nancy Faeser, said: “Our security authorities have prevented potential explosive attacks intended to strike at and undermine our military help for Ukraine.”

Faeser said Germany would not be cowed by the attacks. “We will continue to hugely support Ukraine and will not let ourselves be intimidated,” she said.

The justice minister, Marco Buschmann, called the arrests an “investigative success in the fight against Putin’s sabotage and espionage network”.

“We know that the Russian power apparatus also has our country in its sights. We must react to this threat defensively and determinedly,” he said, without naming specific measures.

Putin’s spokesperson, Dmitry Peskov, told reporters on Thursday that the Kremlin did not possess any information regarding the arrests.

There have been several Russian spy incidents in Germany in recent years, including a former security guard working at the British embassy in Berlin who was paid by the Russian state to spy on its behalf.

A growing number of hacking attacks, in particular of the Bundestag, have been attributed to Russia-affiliated agents.

Last month a conference call between a group of Germany’s top military generals was intercepted by Russia, with its leak via Kremlin-backed TV causing widespread embarrassment and concern in Berlin and prompting a tightening of security regulations.

Diplomatic relations between Berlin and Moscow have been hugely scaled back since February 2022, with many Russian diplomats forced to leave the country.

Germany is home to a large Russian-speaking diaspora, many of them holding dual citizenship. In particular since Russia’s full-scale of invasion of Ukraine, thousands of Russians have been granted asylum in Germany, many of them having wanted to escape military service.

In recent months there has been an increasingly vocal debate about whether this inflow of Russian citizens might pose a security threat for Germany, as one of the largest donors of military support to Ukraine, as well as one of the countries to have taken in a considerable number of Ukrainian refugees.

According to German practice, suspected criminals are identified using only the initial letter of their surnames.

Some time in the pre-dawn darkness, the commotion starts. From her bed, Danae Mossman hears the noise building: loud romantic liaisons, vomiting, squeals, the sound of bodies hitting the pool at full tilt.

Things get particularly loud between midnight and 4am, Mossman says, “when they are getting busy”.

Mossman’s hard-partying housemates are a flock of kororā, or little penguin, the world’s smallest, which have formed a growing colony beneath her house in the Wellington suburb of Karaka Bays on the Miramar peninsula. They use her lily ponds for pool parties, and during nesting season, they create a stink.

“They go out and get fish, regurgitate it and eat that for three days.”

New Zealand’s Department of Conservation encouraged the birds to move to specially built nests closer to the sea, but so far they have shown no desire to leave. So Mossman has come to embrace her housemates, even installing a ladder in the ponds so the penguins can clamber out.

“We figured if they were happy and safe under our home, then we wouldn’t want them any place they were more vulnerable,” Mossman says. “The most annoying thing about them being under the house is how loud they are.”

In many cities, forests and ecosystems around the world, the sounds of nature are falling silent. But in New Zealand’s capital, people are experiencing a crescendo in birdsong, thanks to decades of conservation efforts. Some species, such as the kororā, are still at risk, but many native birds have bounced back in their thousands, transforming the city’s morning chorus.

‘The dawn chorus is so loud, we have to shut the doors’

In the dark, still moments as Wellington wakes and the hum of traffic builds, the city’s birds begin to sing.

First comes the tūī’s high, clear trill, slicing through the dawn. The melodious bells of korimako join, followed by the pīwakawaka with its kiss-like squeaks. As the horizon lightens, kākā – large brown parrots – fleck the sky, waking residents as they swoop and screech.

Fifty years ago, when Jack and Jill Fenaughty bought their then bare, rugged farmland in Mākara – 25 minutes from the city centre – they were lucky if they encountered an introduced bird species, let alone a native one.

“You saw hardly any native birds,” Jill says. “Now,” Jack jumps in, “the dawn chorus is so loud, we have to shut the doors if we want a lie-in.”

The majority of UK dairy farms are breaking pollution rules, with vast amounts of cow manure being spilled into rivers.

When animal waste enters the river, it causes a buildup of the nutrients found in the effluent, such as nitrates and phosphates. These cause algal blooms, which deplete the waterway of oxygen and block sunlight, choking fish and other aquatic life.

Sixty nine per cent of the 2,475 English dairy farms inspected by the Environment Agency between 2020 and 2021 were in breach of environmental regulations, according to new data released under freedom of information laws.

The problem is prevalent across the UK; in Wales 80% of the 83 dairy farms inspected by Natural Resources Wales between 2020 and 2022 were non-compliant with anti-pollution regulations. In Northern Ireland 50% of the 339 dairy farms inspected by the Department of Agriculture, Environment and Rural Affairs between 2020 and 2022 were not compliant, and in Scotland 60% of the 114 dairy farms initially inspected by the Scottish Environmental Protection Agency between 2020 and 2023 were in breach of regulations.

Campaigners have linked this pollution scandal to that caused by the sewage crisis because it also involves ageing infrastructure and intensification of effluent discharges.

They say that pricing pressures from supermarkets, where farmers are offered very little for milk, have caused producers to intensify their production by increasing the number of cows they keep.

Charles Watson, the chair of the charity River Action, said: “The unacceptable pollution levels caused by the UK dairy industry is not dissimilar to the current UK sewage pollution crisis: aged infrastructure, designed for much lower volumes of effluent, being overwhelmed by the combination of intensification of use and more volatile weather conditions.”

“With a herd of 50 cows calculated to be capable of emitting the equivalent amount of pollution as a human settlement of 10,000 people, it is hardly surprising that the dairy industry is placing an unsustainable pollution burden on many river catchments across the country. Meanwhile, yet another chapter in the British river pollution scandal unfolds, our impotent regulators continue to watch on in a solely advisory capacity, and the giant supermarket groups happily count their profits at the cost of the continuous degradation of the environment.”

River Action is calling for dairy processors to offer incentives to farmers who produce milk responsibly, either by less intensive farming or by investing to dispose of cow muck responsibly.

It is also asking for a strengthened response from regulators, asking them to fully enforce existing anti-pollution rules. Many farms go years without inspections because regulators do not have enough staff owing to underfunding. River Action has asked the devolved national bodies responsible to expand and extend existing grant schemes to improve the infrastructure for slurry management.

The Department for Environment, Food and Rural Affairs said: “We have set ambitious legally binding targets to reduce water pollution from agriculture and are taking wide-ranging action to clean up our waterways. This includes investing £74m in slurry infrastructure to help farmers cut agricultural runoff and rolling out new farming schemes to thousands of farmers to deliver environmental benefits and adopt more sustainable practices – all to reduce the amount of nutrients entering rivers.”

Research has estimated the health impacts from the coal-fired power plants that operate across India.

Six hundred coal power plants generate more than 70% of India’s electricity. Despite regulations passed in 2015, fewer than 5% of these plants operate with modern systems to clean up air pollutants from their chimneys. In China, 95% of coal-fired power plants were fitted with clean-up technologies by 2013.

Dr Asif Qureshi of the Indian Institute of Technology in Hyderabad and his team used a computer simulation of air pollution across India to test what would have happened if new technologies had been fitted to the power plants. They looked at two different technologies and found that controlling sulphur was the most effective single step, but applying both technologies together yielded the greatest gains.

As many as 720,000 early deaths could have been avoided over a 10-year period if the power plants had been cleaned up in 2010. Particle pollution would have reduced by up to 11% across the country. The research team found that people living around power plants would have experienced the greatest benefit, up to a 28% reduction in particle pollution, leading to about a 17% reduction in early deaths.

Installation and running costs are often cited as a reason to delay. Qureshi’s team therefore compared the cost of clean-up systems to the cost of the lives lost.

The capital and operating cost were estimated to be between $19.5bn and $32.8bn (about £16-26bn) a year. The benefits depend on the monetary value assigned to a human life. Using a range of international values the researchers calculated a benefit of between $18bn and as much as $604bn US dollars (about £14-481bn).

Qureshi said: “Even at this screening level there appears to be a strong case to implement clean-up technologies. If the industry or the policymakers could buy into this way of looking at the problem, maybe pollution control can be accelerated.”

Prof Maureen Cropper of the University of Maryland in the US led an earlier study on the impacts of planned coal power stations in India. Rather than focus on power plants that were already built, Cropper’s team looked at future options.

Cropper said: “There are large health co-benefits from switching to renewable energy from coal-fired power plants. Not building the future coal capacity that was planned in India in 2019 would avoid at least 844,000 premature deaths over the lives of these plants.”