In a searing dissent Thursday, Justice Ketanji Brown Jackson slammed her fellow justices’ decision to dismiss the case over whether a state can ban abortions to protect women’s health, pointing out that the dismissal will drag out the case – and potentially endanger Americans.

“Will this court just have a do-over, rehearing and rehashing the same arguments we are considering now, just at a comparatively more convenient point in time?” Jackson asked in a dissent read from the bench, a move justices tend to only make when they feel particularly fired up.

“Or maybe we will keep punting on this issue altogether, allowing chaos to reign wherever lower courts enable states to flagrantly undercut federal law, facilitating the suffering of people in need of urgent medical treatment.”

The case deals with whether Idaho’s abortion ban, which only permits abortions in cases where a woman’s life is in danger, violates a federal law known as Emergency Medical Treatment and Labor Act (Emtala). That law, which dates back the 1980s, requires hospitals that receive federal dollars – which is virtually all of them – to stabilize the health of patients who show up at their emergency rooms in the midst of medical emergencies.

The Biden administration had sued Idaho, arguing that its abortion ban forced doctors to break federal law by leading them to withhold abortions until women were on the verge of death. The supreme court initially issued an order allowing Idaho’s abortion ban to take full effect but, in its Thursday dismissal of the case as “improvidently granted” – indicating they should have never taken it on – the justices agreed to let Idaho doctors resume performing emergency abortions.

“We cannot simply wind back the clock to how things were before the court injected itself into this matter. Our intervention has already distorted this litigation process,” Jackson said in her dissent. “We permitted Idaho’s law to go into effect by staying the district court’s injunction in the first place, then allowed this matter to sit on our merits docket for five months while we considered the question presented.”

Letting the Idaho case continue to play out will also impact the rest of the US, Jackson added. Although many states that ban abortion permit the procedure to protect women’s health, a handful do have bans on the books that, like Idaho, only allow abortions to save a patient’s “life”. These bans could conflict with Emtala, according to briefing in the supreme court case by the Biden administration.

Notably, Texas has also already sued the Biden administration over Emtala. The state’s claim in that suit was that the landmark law protecting emergency abortion access was “an attempt to use federal law to transform every emergency room in the country into a walk-in abortion clinic”. Courts have since sided with Texas, blocking Biden administration guidance about Emtala and emergency abortions from taking effect in Texas.

The dismissal in the Idaho case does not impact the Texas litigation. The Texas Emtala case could land in front of the supreme court as early as next term, Nancy Northup, the president of the Center for Reproductive Rights, told reporters in a call on Thursday.

A final decision in the case may not arrive until after the November elections. If Donald Trump wins the presidency, his administration could decide to shift its priorities, change the executive branch’s interpretation of Emtala and stop litigating the case, according to Nicole Huberfeld, a health law professor at Boston University’s School of Public Health. If that happens, Idaho’s abortion ban may end up remaining as is.

“As someone who cares about access to care, this decision is just a temporary reprieve,” Huberfeld said. “It’s not the end of the line.”

Jackson effectively sided with the 6-3 vote to dismiss the case, in that she agreed with the move to let emergency abortions resume in Idaho but said she would not have dismissed it as improvidently granted. To the extent that Emtala is in conflict with Idaho’s ban, she wrote, the federal law trumps state law.

“This months-long catastrophe was completely unnecessary,” Jackson said.

She continued: “This court had a chance to bring clarity and certainty to this tragic situation and we have squandered it. And for as long as we refuse to declare what the law requires, pregnant patients in Idaho, Texas and elsewhere will be paying the price.”

A Canadian man has made history by receiving zero votes in a contested federal election, after running as part of a protest over the lack of electoral reforms in the country.

“When I saw the result, I was like: ‘Well, I am the true unity candidate. Everyone agrees not to vote for me,’” Félix-Antoine Hamel told CBC News.

Hamel was among 84 people who listed as a candidate in a recent by-election held in Toronto. He put his name forward as a candidate after he was approached by the Longest Ballot Committee, which works on electoral reform advocacy.

As a key campaign promise, Justin Trudeau promised that if his party won power, the 2015 federal election would be the last under the first-past-the-post system. After his government won a landslide majority, however, he abandoned the promise.

The Longest Ballot Committee says the current system skews power into the hands of parties wining a minority of the vote. In protest, the group successfully put 77 names on the Toronto ballot, bringing the total to 84 and slowing efforts count votes in Monday’s closely-watched election. Scrutineers were forced to sift through paper ballots measuring a meter in length: the longest ever in Canadian history.

“The unusual dimensions of the ballot itself meant that some steps took more time than normal,” an Elections Canada spokesperson said in a statement. “Delays compounded across several steps over the course of the night.”

When the results had been finalized, six other candidates received two votes each, but Hamel was the candidate one not to receive a single vote.

Hamel lives hundreds of miles away from the electoral district, in Montreal, and because he lives outside Toronto, he couldn’t vote for himself.

Previous federal elections have seen zero-vote results, but in those cases, the candidates were running unopposed and were thus acclaimed as winners. Hamel’s feat marks the first time someone has won zero votes – and lost.

“I’m one of the last people that would be expected to make Canadian history in any way,” he said.

BrewDog has been accused of sacking an Asian woman after she voiced her distress when members of the far-right English Defence League met in the London bar where she worked.

The former staff member said members of the EDL had gathered unchallenged at the “punk” brewer’s flagship bar in Waterloo, ahead of a rally to mark St George’s Day on 23 April.

Police went on to arrest 10 people at the event, after groups of men tried to break through cordons in an areas of Whitehall, while glass bottles were also thrown.

The former BrewDog staff member said she had gone to see her manager in a podcast studio located in the bar after she arrived at work to find that suspected members of the EDL were drinking in the bar before the rally.

BrewDog accused her of “aggressive behaviour and use of inappropriate language” after she raised her concerns, according to documents seen by the Guardian.

“This was not the case at all,” Myriam – not her real name – told Tribune magazine, which first reported the story.

“All I said was ‘I can’t fucking believe this. This is fucking unbelievable.’ I didn’t swear at my manager … When I read the accusation, it completely broke me. I was scared, upset, heartbroken. I felt powerless. This is my job. I have bills to pay. I had a breakdown.”

Myriam sent a message to her manager apologising for the strength of her emotions and asked him to put himself “in the shoes of a brown woman in this situation”, adding that her family had faced racial abuse from the EDL when she was growing up.

In a letter to Myriam, BrewDog said it acknowledged her “past trauma and emotional state” but that she had been guilty of serious misconduct worthy of dismissal with notice.

The trade union Unite said it was concerned about BrewDog’s treatment of staff. “We shall be doing everything we can legally and industrially to ensure that our members at this and every Brewdog receive the justice they deserve,” said Bryan Simpson, lead organiser at Unite Hospitality.

While the EDL did not make a booking at the BrewDog bar, Myriam said they were “allowed to sit there and drink before their rally, which always end up violent”.

BrewDog, based in Aberdeenshire, is understood to have been informed by police a day earlier that EDL members were likely to gather in the Waterloo area and might visit the bar. Police told the company not to close the venue and offered assurances that officers would be present.

Myriam said staff were not told about this and said the lack of advance warning was a factor in her reaction. Colleagues were extremely uncomfortable about the presence of the EDL and one was in tears, she claimed.

One member of BrewDog staff who dealt with her disciplinary hearing appeared to be unaware of what the EDL was, she added.

BrewDog, which built a reputation as a “punk” challenger to mainstream beer brands, has faced multiple allegations of poor treatment of staff.

In 2021, the company apologised to former employees who accused the company and its co-founder, James Watt, of fostering a “culture of fear” in which workers were bullied and “treated like objects”.

Watt has since stood down as chief executive, saying he wanted to focus on other ventures, although he remains on the board.

BrewDog told Tribune: “The standards of behaviour we expect from our colleagues are set out in our workplace code of conduct. There was a clear and unacceptable breach of this code in this instance. We followed all relevant processes and complied with our investigation and disciplinary policies, and we stand by our decision.”

The Guardian has approached the company separately for comment.

A vast sinkhole has dramatically appeared in middle of an Illinois soccer pitch that was laid above a limestone mine, just days after amateur teams stopped using the grounds for practice.

The collapse happened at Gordon Moore Park in Alton, Illinois, about 18 miles (30km) north of St Louis, Missouri, on Wednesday. The sinkhole appeared to be 100ft (30m) wide and 30ft (9m) deep. No injuries have been reported but all sports have been cancelled.

“No one was on the field at the time and no one was hurt, and that’s the most important thing,” said Alton’s mayor, David Goins, in a post on Facebook.

Mine operator New Frontier Materials said in a statement there was a “surface subsidence”, according to local news reports. The director of the Marquette Catholic high school athletic club, Brian Hoener, told the Alton Telegraph the effects of the collapse could have been “much worse”.

“Last week at that time, we had 60 to 70 people out there on the field for our soccer camp,” he said.

The Alton parks and recreation director, Michael Haynes, told NBC affiliate KSDK of St Louis that the collapse “looks like something out of a movie, right? It looks like a bomb went off.”

Haynes said that Alton administrators were waiting to hear back from the mining company and to see “what the geologists and the engineers have to say about it”.

“We’ll follow their lead on where to go from here,” Haynes added. “They can determined what happened, why it happened, how to prevent it and how we fix what has happened here.”

According to studies, an increase in the occurrence of sinkholes are an “overlooked” aspect of climate change compared with other geo-hazards and typically mostly attributed to subsidence and groundwater pumping.

The US Geological Survey also says sinkholes have been correlated to land-use practices, especially from groundwater pumping and from construction and development practices.

A spokesman for New Frontier Materials said: “Safety is our top priority” and the company would “work with the city to remediate this issue as quickly and safely as possible to ensure minimal impact on the community”.

The company said the collapse had been reported to the Mine Safety and Health Administration.

A group of prominent Israelis – including a former prime minister and an ex-head of Mossad, the foreign intelligence service – have added their voices to the growing domestic calls in the US for Congress to withdraw its invitation to Benjamin Netanyahu to address it next month, calling the move “a terrible mistake”.

The plea, in an op-ed article in the New York Times, argues that the invitation rewards Netanyahu, Israel’s current prime minister, for “scandalous and destructive conduct”, including intelligence failures that led to last October’s deadly Hamas attack and the ensuing bloody war in Gaza which shows no sign of ending.

“Congress has made a terrible mistake. Mr Netanyahu’s appearance in Washington will not represent the State of Israel and its citizens, and it will reward his scandalous and destructive conduct toward our country,” the article’s six authors argue in a blistering critique that also accuses the Israeli prime minister of failing to secure the release of scores of hostages taken in last year’s attack and still held captive.

The article’s authors were Ehud Barak, a former prime minister; Tamir Pardo, an ex-director of Mossad; David Harel, the president of Israel’s academy of sciences and humanities; the novelist David Grossman; Talia Sasson, a former director in the state attorney’s office; and Aaron Ciechanover, a Nobel prize-winning chemist.

Their august status and biting criticism will reinforce the opposition of many Democrats to Netanyahu’s appearance before a joint session on Capitol Hill on 24 July – a sentiment strengthened by his accusation last week that the Biden administration is hampering Israel’s war effort by deliberately withholding weapons, a charge the White House denies.

The invitation was originally extended by the Republican House speaker, Mike Johnson, and endorsed by Hakeem Jeffries, the Democratic House minority leader, and the Democratic Senate majority leader, Chuck Schumer, despite the latter’s earlier denunciation of Netanyahu and call for fresh Israeli elections.

Several Democrats have said they will boycott Netanyahu’s congressional appearance, most notably Bernie Sanders, the leftwing senator for Vermont, who has branded the prime minister “a war criminal”.

Jim McGovern of Massachusetts, the ranking Democrat in the House rules committee, has called the invitation to Netanyahu “deeply troubling” and also vowed to stay away. Other critical Democrats have included former House speaker Nancy Pelosi.

In comments that will be grist to the Democrats’ mill, the six Israelis write: “Inviting Mr Netanyahu will reward his contempt for US efforts to establish a peace plan, allow more aid to the beleaguered people of Gaza and do a better job of sparing civilians.

“Time and again, he has rejected President Biden’s plan to remove Hamas from power in Gaza through the establishment of a peacekeeping force.”

Setting out the domestic opposition to Netanyahu among Israelis, they add in a scathing conclusion: “Giving Mr Netanyahu the stage in Washington will all but dismiss the rage and pain of his people, as expressed in the demonstrations throughout the country. American lawmakers should not let that happen. They should ask Mr Netanyahu to stay home.”

One morning in the winter of 1978, a handful of state wildlife staff huddled together in the Uinta Mountains in north-eastern Utah. Deep snows coated the peaks and filled the valleys. A pair of helicopters cruised over the frozen landscape, helping those on the ground search for their prize: a cow moose in a snowy meadow.

Crouched in one of the aircraft, a man aimed his rifle: there was a sharp report, and the cow took off at a run. Within minutes her legs went wobbly as the tranquilliser in the dart took effect, and the crew landed and got to work.

They tagged and collared the moose, then slid a specially designed sling under her belly, attached by a rope to one of the helicopters. For a moment, as the pilot eased into the air, the moose lurched, drawing her legs upward as her feet left the ground.

But then the animal appeared to relax as she soared over the rugged valley, bound for her new home more than 200 miles away in Colorado’s North Park region near Walden– a vast expanse of sagebrush and willow between two mountain ranges.

Few creatures evoke the American wilderness like Alces americanus, the American moose. It is the second-largest land animal in North America, behind the bison. Its imposing size is undercut by a goofy countenance – the wide fan of horns, thin legs that suspend a hefty body and a face like a hand- puppet fashioned from a worn-out sock.

Despite their ungainly appearance, however, moose are formidable and sometimes graceful, reaching speeds of 35mph at full gallop. Over time, in Colorado, the moose has emerged as a potent symbol and ambassador of the wild in a state enamoured of its outdoor places, depicted in murals and statues in many mountain towns.

But as much as Alces americanus seems to belong in Colorado, its native range does not extend into the state. Colorado’s wildlife department introduced moose in the 1970s to help generate revenue through the sale of hunting licences. In that era of wildlife management, the decision of a few high-ranking state officials was enough to set a great ecological experiment into motion.

“We brought them to Colorado because we could,” said the late Gene Schoonveld, a biologist at the forerunner to Colorado Parks and Wildlife, who was among the officials to set the translocation in motion (Schoonveld died in 2022). “We had the space and the habitat for them.”

Now, that experiment is reaching a head, and thousands of wild moose roam the state’s woodlands and mountains – coming into increasing and often deadly conflict with humans.

Though they are notoriously hard to count, there are now an estimated 3,000 moose scattered through Colorado’s major mountain ranges. That figure, however, does not adequately describe their growing presence – or the way they have transformed the landscape. The comment sections for dozens of hikes on the popular AllTrails app now contain a litany of moose sightings.

Moose have even made their way into the suburban sprawl of Denver, the state’s capital, browsing in the green belt, sauntering across golf courses or loitering in shopping centre car parks.

As Colorado’s human and moose populations have grown, so have the number of conflicts between them. Moose attacks in the state now outnumber attacks by bears and pumas (also known as mountain lions or cougars) combined, even though moose numbers are significantly lower.

Over two weeks in the spring of 2022, moose attacked people in three separate incidents. Near the mountain town of Nederland, a cow moose trampled and severely injured a hiker and a dog; a police officer shot her and wildlife officials took her calf into custody. In September 2022, a moose gored and nearly killed a bowhunter in northern Colorado after the hunter’s arrow whistled wide of its mark. More often than not, however, moose come out on the losing end of these clashes. According to the Colorado Department of Transportation, cars struck and killed 59 moose in 2022. In 2012, the number was just four.

In State Forest park, where officials originally released moose in 1978, as many as 700 now roam the area. “It’s the last frontier,” says Tony Johnson, a State Forest ranger. “There are no chain stores, but moose on every corner.”

Human values have always shaped wildlife policy. In Colorado and elsewhere in the American west, mountain goats, elk and bison have been introduced to places where they never lived before or have been sustained in unnaturally high numbers to satisfy hunters and wildlife watchers. Those efforts have frequently changed the environment dramatically.

Amid the rich willow stands of North Park, the two dozen transplanted moose flown to the state kicked into reproductive overdrive, with many producing two offspring at once – a phenomenon called “twinning” that occurs when food is especially plentiful. A decade after their introduction, the moose population had grown to about 250.

The animals proved so successful and popular with residents and visitors that, between 1987 and 2010, wildlife officials transplanted more moose to other parts of Colorado, where they also thrived.

“Biologists generally expected them to do well,” Eric Bergman, a research scientist and moose specialist with Colorado Parks and Wildlife, “and they certainly did.”

Rocky Mountain national park, just east of North Park, is among the places that have witnessed that rapid growth. Park biologists estimate that 40 to 60 moose now wander the western side of the park.

At the Rocky Mountain park headquarters, a landscape ecologist, Will Deacy, shows an infrared image of a mountainside covered in dark trees. A closer look revealed white silhouettes scattered among the pines: moose going about their mysterious business. “They are a new species in a new context,” Deacy said. “There is so much we just don’t know.”

One of those unknowns is just how moose will affect a landscape already heavily browsed by native elk. Settlers nearly hunted elk to extinction in this part of the state, but in 1913, officials reintroduced them within the protective boundaries of the national park. By the late 20th century, elk here also no longer faced predation by wolves or grizzlies.

The herd ballooned to as many as 3,500 animals by the early 2000s – far more than the maximum of 2,100 that the park service deem sustainable – and rapidly chewed through willow stands. The park’s willows, a keystone species throughout the Rockies, declined by 96% between 1999 and 2019.

With moose now inhabiting every major valley within the park, there is a fear that these larger animals could have a similar impact.

According to biologists, an adult moose can eat up to 27kg (60lb) of willow a day, far more than an adult elk, which consumes roughly a third of that amount of forage, only a fraction of which is willow. And because national parks ban hunting, moose tend to congregate within their borders, achieving densities almost five times higher than outside them.

That could create new problems for willows and the myriad creatures that depend on them. Research in Grand Teton and Yellowstone national parks by Joel Berger, a wildlife biologist at Colorado State University, found that migratory songbirds, such as warblers and flycatchers, occur at much lower densities where there are large populations of moose.

“People love their moose,” says Elaine Leslie, former chief of the National Park Service’s biological resource management. But too many of the animals could threaten “the primary purpose of the park, which is the preservation of resources”.

Leslie sees a potential solution in the reintroduction of wolves to Colorado, which brought 10 animals to the central Rockies in December 2023. Wolves are the main predator of elk and moose, and could ease pressure if they recolonise an area and reduce populations or induce herds to keep moving.

If natural means of moving moose do not work, the park might be forced to explore other, more extreme options such as darting the animals with contraceptive drugs or, in the worst case, culling them.

While Leslie calls moose “one of my favourites,” she says: “I’m worried about what is happening at the ecosystem level, especially in Rocky Mountain national park. That is a very biodiverse area right now.”

Despite growing pains as Coloradoans figure out how to co-exist with this large, non-native ungulate, the state has become something of a de facto refuge for the species. Moose populations in much of their native range across the northern US are plummeting.

In New Hampshire, they declined by nearly half from the mid-1990s to late 2010s, owing to habitat loss and warming temperatures, which triggered a sharp rise in ticks. Wyoming was a stronghold of the species, but today Colorado has more moose than its northern neighbour. And there are signs that Colorado’s moose numbers may be naturally stabilising: lower pregnancy rates and animals skipping breeding.

Communities are learning to coexist with the animals. In Walden, moose are such frequent visitors that a sign outside town proudly proclaims it to be the “Moose viewing capital of Colorado”.

“We have them in town quite often,” said Josh Dilley, State Forest’s park manager. They especially like to congregate around the elementary school, he explained, “so we’ll go sit strategically between the moose and the kids while they’re going to school.” When moose loiter too long in front yards and public parks, rangers scare them away with firecrackers or non-lethal rubber buckshot. On rare occasions, they sedate an unruly moose with a dart and take it elsewhere by truck.

Still, Leslie warns, without stronger controls and monitoring, Colorado could face increasingly denuded stream banks, more frequent attacks and car collisions – and more moose in the crosshairs.

“It’s partly everybody’s fault – the state and the feds – because we don’t think into the future very well and we don’t learn from history,” Leslie says. “Unless everybody gets on the same page, it’s going to get ugly.”

Dominga Menezes was only 12 years old when she danced for a dictator.

It was 25 July 1974, and São Leopoldo, a medium-sized city in Brazil’s southernmost state, Rio Grande do Sul, was celebrating both the anniversary of its founding and 150 years of German immigration to Brazil.

Then leader of Brazil’s military dictatorship, Gen Ernesto Geisel was himself of German descent, and was guest of honour at the ceremony next to the Sinos River, where the first German immigrants had arrived in 1824.

One hundred and twenty girls danced onstage, each wearing a leotard with one of the three colours of the state flag.

“The whitest girls were wearing green; the Black girls, red; and the light-brown-skinned were in yellow,” said Menezes, now 62. “It was much later that I realised the teachers had put me in yellow because I’m of Indigenous descent.”

She does not know why each race was associated with each colour. But she remembers that, in school, the students with more “German” physical characteristics – fair skin, blue eyes and blonde hair – were the ones praised by the teachers.

“Every year at school, in July, there was a lot of talk about German immigration. But they never raised the question of who else was here: the Indigenous people and the Black people,” said Menezes.

This year, as São Leopoldo celebrates its 200th anniversary and the bicentenary of German immigration, things were supposed to have gone differently: diversity was a central theme of a string of events planned by the city hall.

But those plans were thrown into disarray by the unprecedented flooding that devastated Rio Grande do Sul.

Although São Leopoldo was not wiped out by the disaster – as was the case with others, such as Eldorado do Sul – parts of it spent almost a month under the muddy water.

Nine people died, and 100,000 of its 217,000 residents had to leave their homes.

When water finally receded in late May, the city was left to face the aftermath.

“The biggest problem now is psychological. Families have lost the school as a reference point, the health clinic, and their church. They’ve lost everything,” said the city mayor, Ary Vanazzi, 64.

His house spent more than 20 days submerged; everything inside of it was lost.

At Visconde de São Leopoldo Historical Museum, about 10% of the 10,000 artefacts in its collection, all of them related to German immigration, went underwater.

The most affected piece was a 120-year-old Schiedmayer grand piano. The keys are covered in mould, what is left of the strings are rusted, and pieces of what used to be the soundboard are warped.

Museum staff are hoping to reopen in time for 25 July, when the bicentenary is celebrated, said historian Rodrigo Luiz dos Santos, 39. “Even if it’s with a smaller exhibition … From the perspective of culture, of the city’s memory, we think it’s important to have this moment,” he said.

Speaking at the G7 summit in Italy, Brazil’s president Luiz Inácio Lula da Silva said that he invited representatives of the German government to attend a bicentennial “celebration party” in São Leopoldo.

But, according to the mayor, there will be only a symbolic celebration.

“There’s no mood for anything like that … We’ll celebrate it in a different way, perhaps with more solidarity,” said Vanazzi.

Inside the museum, a dirty brown line 1.5 metre from the floor shows the high water mark, and dos Santos suggested that one of the walls would be left without repainting as a reminder of the floods.

“The same river that brought the immigrants was the one that 200 years later took over the city,” he said.

About 40 Germans were in the first wave of immigrants who came to the region in 1824.

Other people from the then German Confederation had previously reached Brazil, but from that moment German migration became continuous, later spreading to other regions of the state.

Its cultural impact can still be felt in regional culture, for example in its most traditional cake, the cuca, a version of the German streuselkuchen.

German migration was encouraged by newly independent Brazil, which wanted to expand its occupation of the territory. But the promotion of European immigration was also linked to the idea of “whitening the Brazilian population”, said dos Santos.

“There is no street in São Leopoldo named after a Black or Indigenous person,” said Dominga Menezes, who still lives in São Leopoldo and, now a journalist, recently published a book about how the focus on German migration has silenced Black and Indigenous stories in the region.

She and her husband, fellow journalist Gilson Camargo, 61, describe countless conflicts between the Germans and the Indigenous communities who inhabited the region and were practically wiped out.

They also highlight something that is still controversial in some parts of the state: the fact that many of the immigrants were slave owners.

The book was launched in the city’s public library only a week before the floods.

“Despite all the sadness, I think we need to learn a lesson from this,” said Menezes, who drew a parallel between the city’s reckoning with its past and its response to the recent disaster.

“When the floods started, people said it wasn’t the time to find who was responsible – but that was a way of not facing up to the problems.

“People must know what happened was an environmental tragedy, but it was also caused by humans … We cannot deny history once again,” said Menezes.

An onslaught of record-breaking heat across much of the US has provided yet another indicator of a longer-term issue – summers are progressively getting hotter for Americans in all corners of the country.

The US climate scientist Brian Brettschneider has analysed almost 130 years of federal data and it shows that from New York to Los Angeles summers have got significantly hotter in that time compared with the average levels of warming brought about by the burning of fossil fuels.

Summers are, on average, now about 0.8C (1.5F) hotter across the US than this earlier period, but many places have had far more extreme summertime increases, being up to 2.8C (5F) hotter.

More than a third of people in the US live in a county that has summers 1.5C (2.7F) hotter, or more, than they were on average in 1895, Brettschneider’s analysis of federal government data shows. This means that about 117 million Americans are experiencing these new conditions, with 55.7 million of these people in counties that have heated up by 2C (3.6F) or more.

A smaller, but significant, number of people, about 12 million, live in places that have heated up 2.5C (4.5F) or more over summer since the 19th century. Globally, the average year-round temperature is slightly more than 1C (1.8F) warmer than it was in pre-industrial times, with last year the hottest ever recorded, the latest in a string of record annual highs.

“Summer is a time is when we are hyper-aware of warm temperatures and many of us are feeling that right now,” said Brettschneider, a climate scientist who compiled the county-level figures drawn from National Oceanic and Atmospheric Administration (Noaa) temperature data for the summer months stretching back to 1895.

The fastest-warming counties span places with sparsely populated desert, rugged mountains and breezy coastal cities, with the three highest temperature increases over summer occurring in Grand county, Utah; Ouray county, Colorado; and Ventura county, California. The counties that include Los Angeles, Baltimore and Phoenix all have summers 2.2C (4F) or more hotter than the prior average, while the heart of New York City is 2.1C (3.8F) warmer.

Regional temperature discrepancies are influenced by factors such as natural variation and land-use changes, as well as the overall warming climate, cautioned Jane Baldwin, a climate scientist at the University of California, Irvine.

Winters are warming more quickly than summers, too. But even seemingly small increases in summer temperatures can have an outsized impact in fueling punishing heat, Baldwin said.

“One degree celsius of warming may sound relatively small but it can translate into quite substantial impacts as it’s an average and the extremes of that average can cause much higher likelihoods of deaths from heatwaves, as well as agricultural impacts and wildfires,” she said.

“Heat is a silent killer and it unfortunately affects the most underserved members of society the worst.”

The dangers of warming summers have already been illustrated this year, with record temperatures baking the US south-west and, more recently, the eastern half of the country.

Prolonged heat of 32C (90F) and more has hit about 80% of the population, lingering in some places for the longest time in decades, the National Weather Service has said, adding that the “early arrival of this magnitude of heat, the duration, abundant sunshine and lack of relief overnight will increase the danger of this heat wave beyond what the exact temperature values would suggest”.

The recent heatwave that engulfed much of the southern US, as well as large parts of Mexico and Central America, was made 35 times more likely due to human-induced climate change, according to a rapid analysis by scientists.

Studies have found that summers are generally getting hotter, including much warmer night-times which reduces the amount of relief people get from the elevated temperatures. Heatwaves are getting fiercer and are moving more slowly as the planet warms, with heat now the largest weather-related cause of death in the US.

“We are now starting to have this complicated relationship with summer,” said Deepti Singh, a climate and extreme events expert at Washington State University. “The extreme events are happening more quickly than the rate of mean temperature warming, which is putting a strain on everything we depend upon as a society.

“If you talk to climate scientists, there’s certainly an anxiety as summer approaches. It can be distressing.”

The county-level map of summer temperature increases shows that the warming isn’t uniform, however, with large jumps in heat across much of the US west and in the north-eastern US.

Summer temperatures have somewhat flatlined in the US south-east, meanwhile, a phenomenon known as a “warming hole” that could be down to reflective particulate pollution or reforestation in the region that has helped ameliorate the overall temperature rise, although much of the south-east still gets extremely hot in summer.

Hotter summers not only mean worsening heatwaves – they also contribute to warmer rivers and streams, affecting wildlife, and increase the risk of giant wildfires. More than 50,000 people died because of smoke from various California wildfires in the decade to 2018, a study released this month found, with worsening smoke starting to erase broader progress made in cutting air pollution in the US over the past 50 years.

“People underestimate how at risk they are from the heat,” said Kristie Ebi, an epidemiologist who specializes in climate change impacts at the University of Washington.

“It’s pregnant women, outdoor workers, people on certain medications – the list of vulnerable people is actually quite long. Humans are pretty darn good at thinking others at risk but that they aren’t. We need to understand we are all at risk from this.”

Ebi said there was also a “misconception” that people already living in hot areas can simply acclimatize to extra heat, warning that everyone should check on neighbors, and seek shade, water and cooling when temperatures climb. “There are physiological limits that we all face,” she said.

Longer-term, the hotter summers will keep coming as long as humans continue to expel planet-heating emissions, scientists caution. “Until we stop burning coal, oil and natural gas, conditions like this week’s dangerous heat will become more and more common,” said Andrew Pershing, vice-president of science at Climate Central.