Hurricane Oscar has become the 10th hurricane of the 2024 Atlantic season, battering the Turks and Caicos Islands on Saturday night and the far southern Bahamas on Sunday.

The disturbance that eventually became Oscar was initially given a low chance of tropical development by the US National Hurricane Center. It began on 10 October as a tropical wave across western Africa, bringing thunderstorms and gusty winds to the Cabo Verde Islands, before moving westwards over the Atlantic. However, it struggled to become sufficiently organised at it progressed, as dry air inhibited further thunderstorm development.

By early on 19 October, the disturbance had travelled to the north of Puerto Rico, and the chance of further development remained low. However, over the next 12 hours, thunderstorm activity became sufficiently strong and organised for the system to be classified as a tropical storm and named Oscar.

Hurricane hunters flew into the storm and detected a small area of hurricane-force winds, leading to Oscar’s upgrade to hurricane status. Oscar will affect eastern Cuba on Monday, and is then expected to track northwards and rapidly transition to a powerful extratropical cyclone, potentially bringing wind gusts above 70mph to parts of south-eastern Canada later in the week.

Elsewhere in the tropics, the remnants of tropical storm Nadine are expected to redevelop into a new tropical system to the south of Mexico during the early part of this week – tracking westwards with no significant impacts to land.

In Australia, temperatures have continued to trend above average in October, after the warmest August and fourth-warmest September on record. In the past week, large parts of the south and east have had daily highs reaching the high 30s and low 40Cs, several degrees above the October average.

On Thursday, South Australia suffered its highest temperature in 29 years when the town of Coober Pedy reached 43.7C, while temperatures in parts of Queensland at the weekend reached as much as 11C above average. This heat has fuelled several outbreaks of heavy showers and thunderstorms.

Conditions were particularly severe across New South Wales and Victoria on Friday, with torrential downpours causing some flash flooding – one town in Victoria received 50mm of rain in 45 minutes – alongside damage from strong wind gusts, hail stones as large as gold balls, and about half a million lightning strikes.

Over the coming week, heatwave conditions will shift across the continent to northern parts of Western Australia, where night-time temperatures are expected not to drop below 30C in places later this week.

Humanity is “on the precipice” of shattering Earth’s limits, and will suffer huge costs if we fail to act on biodiversity loss, experts warn. This week, world leaders meet in Cali, Colombia, for the Cop16 UN biodiversity conference to discuss action on the global crisis. As they prepare for negotiations, scientists and experts around the world have warned that the stakes are high, and there is “no time to waste”.

“We are already locked in for significant damage, and we’re heading in a direction that will see more,” says Tom Oliver, professor of applied ecology at the University of Reading. “I really worry that negative changes could be very rapid.”

Since 1970, some studies estimate wildlife populations have declined on average by 73%, with huge numbers lost in the decades and centuries before. Passenger pigeons, the Carolina parakeets and Floreana giant tortoises are among the many species humans have obliterated. “It’s shameful that our single species is driving the extinction of thousands of others,” says Oliver.

The biodiversity crisis is not just about other species – humans also rely on the natural world for food, clean water and air to breathe. Oliver says: “I think we will, certainly, in the next 15 to 20 years, see continued food crises, and the real risk of multiple breadbasket failures … that’s in addition to a lot of the other risks that might impact us through fresh-water pollution, ocean acidification, wildfire and algal blooms, and so on.”

Oliver, who is working with the UK government to identify “chronic risks” to the world, was involved in a 2024 report that showed nature degradation could cause a 12% loss to UK GDP. Disease outbreaks, loss of insects to pollinate crops, collapse of fisheries and flooding were among the risks identified. He says we are in an era of mass extinction with “huge uncertainty in where the safe limits are”.

Scientists say human activity has pushed the world into the danger zone in seven out of eight indicators of planetary safety. Under a business-as-usual scenario, biodiversity loss will accelerate, with more species surviving only in zoos.

Environmental breakdown is driving inequality, conflict and injustice. Dr Andrew Terry, director of conservation and policy at the Zoological Society of London (ZSL), says: “Already, we have witnessed environmentally driven famine in Madagascar and mass migration. We will see increased conflict for access to dwindling resources, particularly water and food. We will see increases in major health issues, particularly [due to] urban heat as temperatures increase to intolerable levels and pollution rises.”

Experts warn that ecosystems are starting to approach tipping points – where they shift into a new, degraded state that further reduces their resilience. Terry says: “This will see once rich, wet tropical areas become dry savannahs, or warming ocean currents completely change. This is where we will see massive functional shifts that will impact humanity.”

A loss of connection to the Earth

All over the world, people are noticing nature and species disappearing in the space of a few generations. Tonthoza Uganja is a land restoration expert from Yesaya village in central Malawi, a forest-dependent community with people traditionally eating mushrooms and berries from the wood for sustenance, and using trees for shelter. “We relied on a biodiverse ecosystem to thrive,” says Uganja. But in the past few generations this abundance of nature has dramatically declined. “If you see the changes, they are tremendous. It’s insane,” says Uganja, who is completing a PhD on farming systems and climate change at Bangor University in Wales.

“People’s livelihoods are at the centre of this,” she says. “Biodiversity loss looks complex, but at the end of the day, it comes back to life. As we lose biodiversity, it’s essentially losing parts of ourselves as human beings as well.”

Her comments were echoed in a report by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (Ipbes), which found a market-based focus on economic growth meant the wider benefits of nature – including spiritual, cultural and emotional value – had been ignored.

If we don’t act, Uganja says, “it will be a planet where we have lost our history, because our nature is our history. We’ve lost not just key species – we’ve lost our connectivity to the Earth.”

In central Malawi, Uganja says threats are multiplying, with changing weather systems making crop failures more common. “Climate change has devastating effects. It is bringing a huge shock wave in communities.

“We are on the precipice of shattering Earth’s natural limits – we have not gone there yet, but we are right on the edge.”

A need for urgency

Scientists say the biodiversity crisis must be treated as urgently as climate. There is up to eight times more media coverage of the climate crisis relative to biodiversity loss, but Alexandre Antonelli, the director of science at Kew’s Royal Botanic Gardens in London, believes a shift is occurring. “Every company leader and politician I talk to today, from many countries and backgrounds, seems to recognise the urgency of halting biodiversity loss, and appears genuinely interested in doing something concrete about it. This wasn’t the case five years ago.”

For many, Cop16 is an opportunity for global leaders to meet and compare their proposed actions to protect biodiversity. So far, governments have never met any of their self-imposed targets on nature loss, and experts say that must change urgently. There is “no time to waste”, says Mike Hoffman, ZSL’s head of wildlife recovery. “We cannot just sit by and document loss; we have to act, working with governments, other NGOs, the private sector and communities, to disrupt that trajectory of loss.”

Key issues to be discussed at Cop16 include whether wealthy countries will meet their target of contributing a minimum of $20bn annually for low and middle-income countries by 2025, as well as all nations outlining their domestic targets to protect biodiversity – less than 20% had done so ahead of the meeting.

Oliver believes the root causes of biodiversity loss lie in our worldviews – and this is also where he believes the solutions will be. Changing the “juggernaut” of destruction means changing the way our economy is run and how the education system works, right down to our mindsets and the way we see ourselves as “locked into this degradation”.

“I think the only way we can start to address that mass extinction is if we have more humility in our relationship as part of just one other species in the web of life,” he says. “We have lost that bedrock of pro-nature values … We need to restore that so we don’t have this casual attitude to ecocide.”

Nature restoration not a ‘nice to have’

Many governments are failing to prioritise nature restoration. In August, a study found that butterflies, bees and bats were among wildlife being boosted by the UK’s nature-friendly farming schemes. The following month it was revealed the Labour government would be slashing the nature-friendly farming budget in England by £100m to help fill what ministers say is a £22bn shortfall.

Prof Rob Brooker, head of ecological sciences at the James Hutton Institute, says it is frustrating to see governments deprioritise nature conservation because of financial constraints. “Biodiversity is not a ‘nice to have’ – it is a critical element of delivering action on climate change, health and wellbeing, and sustainable food production,” he says. “Without action, our planet will be further depleted in the decades to come. We will have more hungry people living in a world with a less stable climate, and more extreme weather events.”

Prof Rick Stafford from Bournemouth University, who is chair of the British Ecological Society policy committee, says he has watched the decline of key species he studies in his own lifetime. He first went diving with sharks on the reefs of Indonesia 20 years ago. Now, “they’ve completely vanished, not just in Indonesia but other places”. Their absence is the “new normal”, he says, but it can have cascading effects for marine ecosystems.

Coral reefs are important fish nurseries and help feed more than 500 million people worldwide. Stafford agrees that biodiversity is not just “a ‘nice to have’ thing”. “It’s actually an essential thing,” he says.

He says people don’t understand the urgency of it. “We are very close to those sort of critical limits where we are not going to be able to recover that biodiversity, and it has really big effects on society – it is not just about being able to see some butterflies.”

Moldova’s pro-western president, Maia Sandu, blamed an “unprecedented assault on our country’s freedom and democracy” by “foreign forces” on Sunday night, as a pivotal referendum on EU membership remained too close to call with most votes counted.

Moldovans went to the polls earlier in the day to cast their vote in a presidential election and an EU referendum that marked a key moment in the tug-of-war between Russia and the west over the future of the small, landlocked south-east European country with a population of about 2.5 million people.

With almost 84% of the vote counted, the no vote was ahead on 53%, according to data shared by Moldova’s electoral commission. But the results could yet change as votes are still being counted among the large Moldovan diaspora, which is favourable to joining the EU.

The separate presidential election results showed that incumbent president Sandu topped the first round of the vote with about 38%, but she will now face her closest competitor, Alexandr Stoianoglo, a former prosecutor backed by the pro-Russian Socialists, in the second round.

The double vote in one of Europe’s poorest countries was seen as a crucial test of Sandu’s pro-European agenda, as she had urged Moldovans to vote “yes” in the referendum to affirm EU accession as an “irreversible” constitutional goal.

The narrow results will disappoint Sandu’s supporters and her allies in Brussels. Pre-election surveys indicated that Sandu held a comfortable lead over her main rival, Stoianoglo, and other candidates, while polls suggested that about 60% of voters supported the pro-EU path in the run-up to the referendum.

Sandu, a 52-year-old former World Bank adviser, was first elected president in November 2020, riding a wave of popularity as an anti-corruption reformer with a pro-European agenda.

Since the breakup of the Soviet Union, Moldova has gravitated between pro-western and pro-Russian courses, but under Sandu it had accelerated its push to escape Moscow’s orbit, especially as Russia launched its war in neighbouring Ukraine.

The two ballots were held amid claims by Moldovan authorities that Moscow and its proxies had orchestrated an intense “hybrid war” campaign to destabilise the country and derail its EU path.

“Moldova has faced an unprecedented assault on our country’s freedom and democracy, both today and in recent months,” Sandu told supporters in the capital, Chișinău, on Sunday as votes were being counted, adding that “criminal groups” had tried to “undermine a democratic process”.

“We are waiting for the final results, and we will respond with firm decisions,” she added.

The allegations against Moscow included funding pro-Kremlin opposition groups, spreading disinformation, meddling in local elections and backing a major vote-buying scheme.

In particular, officials accused the fugitive pro-Russian businessman Ilan Shor, a vocal opponent of EU membership, of running a destabilising campaign from Moscow.

Earlier this month, the national police chief, Viorel Cernăuțanu, accused Shor and Moscow of establishing a complex “mafia-style” voter-buying scheme and bribing 130,000 Moldovans – almost 10% of normal voter turnout – to vote against the referendum and in favour of Russia-friendly candidates in what he called an “unprecedented, direct attack”.

On Thursday, law enforcement agencies said they had also uncovered a programme in which hundreds of people were taken to Russia to undergo training to stage riots and civil unrest.

In total, Moldovan officials claimed Russia had spent about $100m this year on Moldova’s electoral processes.

Moldova applied to join the EU after Russia’s full-scale invasion of neighbouring Ukraine, which was harshly condemned by Sandu and many in the country as tens of thousands of Ukranian refugees fled to Chișinău.

Moldova officially began EU accession negotiations in June, though scepticism remains high about the country’s ability to implement the necessary democratic and judicial reforms in the near future.

Observers believe Sandu could now be facing a tricky second-round runoff against a united pro-Moscow opposition front led by Stoianoglo.

Stoianoglo, a former prosecutor general who was dismissed by Sandu, urged people to boycott the referendum or vote “no”, describing it as a “cynical” move to boost Sandu’s popularity.

In an earlier interview with the Guardian, Stoianoglo denied that he was working on behalf of Russia. But he declined to criticise the Kremlin for its invasion of Ukraine and called for improved relations with Moscow.

Australia could toughen the rules regarding the acceptable levels of key PFAS chemicals in drinking water, lowering the amount of so-called forever chemicals allowed per litre.

The National Health and Medical Research Council on Monday released draft guidelines revising the limits for four PFAS chemicals in drinking water.

PFAS (per- and polyfluoroalkyl substances), a class of several thousand compounds, are sometimes referred to as “forever chemicals” as they persist in the environment for long periods of time and are more difficult to destroy than substances such as sugars or proteins. PFAS exposure is wide and not limited to drinking water.

The draft guidelines set out recommendations for PFAS limits in drinking water over a person’s lifetime.

Under the draft, the limit for PFOA – a compound used to make Teflon – would be lowered from 560 ng/L to 200 ng/L, based on evidence of their cancer-causing effects.

Based on new concerns about bone marrow effects, the limits for PFOS – previously the key ingredient in the fabric protector Scotchgard – would be cut from 70 ng/L to 4 ng/L.

In December last year, the International Agency for Research on Cancer classified PFOA as cancer-causing to humans – in the same category as drinking alcohol and outdoor air pollution – and PFOS as “possibly” carcinogenic.

The guidelines also propose new limits for two PFAS compounds based on evidence of thyroid effects, of 30ng/L for PFHxS and 1000 ng/L for PFBS. PFBS has been used as a replacement for PFOS in Scotchgard since 2023.

NHMRC chief executive, Prof Steve Wesselingh, said in a media briefing that the new limits were set based on evidence from animal studies. “We currently don’t believe there are human studies of sufficient quality to guide us in developing these numbers,” he said.

The proposed PFOS limit would be in line with US guidelines, while the Australian limit of PFOA would still be higher.

“It’s not unusual for guideline values to vary from country to country around the world based on different methodologies and endpoints used,” Wesseleigh said.

The US aims for zero concentrations of carcinogenic compounds, while Australian regulators take a “threshold model” approach.

“If we get below that threshold level, we believe that there is no risk of that substance causing the problem identified, whether they be thyroid problems, bone marrow problems or cancer,” Wesseleigh said.

The NHMRC considered setting a combined PFAS drinking water limit but deemed it impractical given the numbers of PFAS chemicals. “There are very large numbers of PFAS, and we don’t have toxicological information for the great majority of them,” Dr David Cunliffe, principal water quality adviser for the SA health department, said. “We’ve taken this path of producing individual guideline values for those PFAS where there is data available.”

PFAS management is shared between the federal government and the state and territories, which regulate water supply.

Dr Daniel Deere, a water and health consultant at Water Futures, said Australians had no need to be concerned about PFAS in public drinking water unless specifically notified. “We are fortunate in Australia in that we have hardly any water that is affected by PFAS, and you should only be concerned if directly advised by the authorities.

Unless advised otherwise, there was “no value in using alternative water sources, such as bottled water, household water treatment systems, benchtop water filters, local rainwater tanks or bores,” Deere said in a statement.

“Australians can continue to feel confidence that the Australian Drinking Water Guidelines incorporate the latest and most robust science to underpin drinking water safety,” Prof Stuart Khan, head of the School of Civil Engineering at the University of Sydney, said in a statement.

NHMRC prioritised a review of the Australian guidelines on PFAS in drinking water in late 2022. The guidelines had not been updated since 2018.

The draft guidelines will remain out for public consultation until 22 November.

Two crew members who were missing following the crash of a fighter jet in mountainous terrain in Washington during a routine training flight have been declared dead, the US navy said on Sunday.

The EA-18G Growler jet from the Electronic Attack Squadron crashed east of Mount Rainier on Tuesday afternoon, according to navy officials. Search teams, including a US navy MH-60S helicopter, launched from the air station to try to find the crew and crash site.

Special forces soldiers trained in mountaineering, high-angle rescue and technical communications were brought in to reach the wreckage, which was located on Wednesday by an aerial crew resting at about 6,000ft (1,828m) in a remote, steep and heavily wooded area east of Mount Rainier, officials said.

The aviators’ names will not be released until a day after their next of kin have been notified, the navy said in a statement on Sunday, adding that search and rescue efforts have shifted into a long-term salvage and recovery operation as the cause of the crash is still being investigated.

“It is with a heavy heart that we share the loss of two beloved Zappers,” said Timothy Warburton, commanding officer of the aviators’ Electronic Attack Squadron.

“Our priority right now is taking care of the families of our fallen aviators. We are grateful for the ongoing teamwork to safely recover the deceased.”

Locating the missing crew members “as quickly and as safely as possible” had been top priority, Capt David Ganci, commander, Electronic Attack Wing, US Pacific Fleet, said on Thursday.

The search took place near Mount Rainier, a towering active volcano that is blanketed in snowfields and glaciers year-round.

Military aircraft training exercises can be dangerous and sometimes result in crashes, injuries and deaths.

In May, an F-35 fighter jet on its way from Texas to Edwards base near Los Angeles crashed after the pilot stopped to refuel in New Mexico. The pilot was the only person on board in that case and was taken to a hospital with serious injuries.

Last year, eight US air force service members were killed when a CV-22B Osprey aircraft they were flying in crashed off the coast of Japan.

A mass shooting during homecoming weekend at Georgia’s Albany State University left one person dead and five others wounded on Saturday night, according to school officials.

Earlier Saturday in Mississippi, authorities said three people were killed and eight others were injured near Lexington, Mississippi, when at least two people fired guns at a group of several hundred people who were at an outdoor trail celebrating a high school football team’s homecoming game victory.

Albany State University’s interim president, Lawrence M Drake II, said the shootings happened on the school’s east campus, according to the Georgia television news station WAGA. He said Georgia’s state bureau of investigation (GBI) is in charge of the case.

“As always, the safety and security of our ASU students, faculty and staff are the number one priority of this institution,” Drake said in a statement Sunday.

Dougherty county coroner Michael Fowler told the Georgia news outlet WALB that a 19-year-old man from Atlanta died at Phoebe Putney memorial hospital in Albany. WALB identified the slain victim as De-Morion Tayshawn Daniels.

Albany State enrolls about 6,000 students.

As of Sunday morning, there had been more than 420 mass shootings across the US so far this year.

The nonpartisan archive defines a mass shooting as one in which four or more victims are wounded or killed.

Annually high rates of mass shootings in the US have prompted some in the country to call for more substantial federal gun control, though Congress has largely been unable or unwilling to implement such measures.

Democratic governors from three states in the so-called blue wall that is key to their party’s aspirations for an electoral college victory delivered closing pitches for Kamala Harris on Sunday as their presidential nominee celebrated her 60th birthday with a visit to church.

Josh Shapiro of Pennsylvania, Tony Evers of Wisconsin and Michigan’s Gretchen Whitmer barnstormed the Sunday morning political shows to talk up the vice-president’s policy agenda – and highlight differences with Republican candidate Donald Trump, 16 days before an election that polls suggest is still on a knife edge.

Acolytes of Trump, meanwhile, attempted to defend the former president’s extraordinary and vulgar rhetoric during a Saturday night rally in Pennsylvania, when he called Harris a “shit vice-president” and exalted the size of the late golfer Arnold Palmer’s penis.

“I don’t want to go back to Donald Trump when he was in charge of the country,” Shapiro told NBC’s Meet the Press.

“Remember the record? I know there’s still some people that have maybe a little brain fog, they don’t remember what it was like under Donald Trump. You had more chaos, you had less jobs, and you had a whole lot less freedom.

“I don’t think we want to go back to a time of chaos. I want a stable, strong leader, and that’s Kamala Harris.”

It also emerged Sunday that Harris has no plans to campaign with Joe Biden before election day on 5 November, a development appearing to confirm recent reports of friction between the two after the 81-year-old president was pressured out of running for re-election over age-related questions.

“The most important role he can play is doing his job as president,” an anonymous White House official told NBC News, which said the decision was mutual following discussions between the campaign and Biden administration officials.

Shapiro joined Evers and Whitmer, his fellow passengers on a weekend blue wall bus tour, for a joint interview on ABC’s This Week, in which the three spoke of polls showing the presidential race virtually deadlocked in all three states.

“Both candidates believe that Pennsylvania is critical – I just think we’ve got a better candidate, a better message, and what we’re experiencing is a whole lot more energy,” Shapiro said.

In Michigan, according to Whitmer, voters were comparing both candidates’ records ahead of the 5 November election.

“While this is going to be close, I’d much rather be playing our hand in theirs,” she said. “We got a better candidate. We’ve got receipts on the issues that matter to the American people, on the economy, individual rights, affordable housing, and we got a better ground game.”

Evers, a two-term governor, pushed back on Trump’s claims that a Harris administration would tank the US economy, using Democratic policies in Wisconsin as an example.

“We have the best economy we’ve ever had, the largest budget we’ve ever had, and we’re in good shape, and people are making more money than they ever made. So we’re in a good place, and it had nothing to do with Donald Trump,” he said.

The swing state governors were speaking as Harris rallied Black voters in another swing state, Georgia, on Sunday with “souls to the polls” visits to two community churches.

“What kind of country do we want to live in – a country of chaos, fear and hate, or a country of freedom, compassion and justice?” she told the congregation of the New Birth Missionary Baptist church in Atlanta.

“The great thing about living in a democracy is that we, the people, have the power to answer that question. So let us answer not just through our words, but through our actions and with our votes.”

Harris has been attempting to shore up support from the Black community, particularly Black men. Polls have warned of a lack of enthusiasm for her campaign, though newer polling from the Howard Initiative on Public Opinion found Harris had built a lead among Black voters in swing states.

Singer Stevie Wonder was scheduled to join her later at a rally at the Divine Faith Ministries International in Jonesboro. That gathering was set to occur ahead of Harris’s interview with civil rights leader Al Sharpton to be broadcast later Sunday on MSNBC.

“We just have to keep doing the work,” Georgia US senator Raphael Warnock – a Black Democrat – said on CBS’s Face the Nation on Sunday. “And the good news is – that’s exactly what Kamala Harris [is] … doing.”

Trump remained in Pennsylvania for an afternoon rally in Lancaster and a photo-op at a McDonald’s restaurant, the day after his bizarre appearance in Latrobe, Palmer’s home town, in which he riffed at length – in an unrefined address – about how well endowed the golfer was with respect to his genitalia.

Republicans appearing on the Sunday talk shows attempted to detract from Trump’s comments and other recent behavior, including suggesting in an interview this week he would use the US military against political enemies.

The South Carolina senator Lindsey Graham lost his composure when questioned about it on NBC’s Meet the Press – and tried to pivot to two recent assassination attempts on Trump, both conducted by pro-Republican persons.

“When you talk about rhetoric, you gotta remember they tried to blow his head off,” Graham said. “He’s been shot at and hit in the ear, and we’re lucky they didn’t blow his head off. And another guy tried to kill him … so I’m not overly impressed about the rhetoric game here.”

Graham also condemned Republican colleagues, including former members of Congress Liz Cheney and Adam Kinzinger, as well as numerous ex-Trump administration officials who have denounced him and expressed support for Harris.

The retired general Mark Milley, the former chair of the joint chiefs of staff, called Trump “fascist to the core”, according to veteran journalist Bob Woodward’s new book War.

“To every Republican voting for her, what the hell are you doing?” Graham said. “You’re supporting the most radical nominee in the history of American politics. When you support her, you’re supporting four more years of garbage policy.”

US House speaker Mike Johnson, a Louisiana Republican, was more restrained – but equally as determined to avoid questions about Trump’s commentary in an appearance on CNN’s State of the Union, suggesting that it was host Jake Tapper who was obsessed with talking about Palmer’s penis.

“The media can pick it apart, but people are going to vote what’s best for their family and they see that in Trump,” he said.

Early in-person voting is under way in numerous states, with voters in Georgia setting a first-day turnout record Tuesday, even as polls have the candidates in a virtual dead heat.

Shapiro said winning over the remaining undecided voters would determine the winner.

“There are people that, frankly, don’t follow this on a daily basis, people that don’t follow the polls. They go to work, they got kids at home, they do their job with their kids and get up the next day,” he said.

“The polls look at a small number. I know it’s a science, but at the end of the day I run into people all the time who just haven’t given it a thought, so we’re going to help them.”

The government has appointed the UK’s first envoy for nature, a former environment campaigner described as “the environmentalist’s environmentalist”, who will be charged with forging global agreement on halting the precipitous decline of species.

Ruth Davis, the new special representative for nature, is in Colombia for the start of two weeks of vital talks that will decide the global response to the biodiversity crisis. The UK has played a leading role in such efforts in the past and Davis helped draw up a global pledge on deforestation that was one of the main outcomes of the UN Cop26 climate summit hosted in Glasgow in 2021.

She will report to the foreign secretary, David Lammy, and the environment secretary, Steve Reed. The appointment of a nature envoy, first revealed by the Guardian, is an initial step in the government’s plan to put the UK at the centre of global efforts to stave off environmental collapse.

Davis previously held senior roles at charities including Greenpeace, the RSPB and Plantlife, and the thinktank and consultancy E3G. She has worked on environmental policy for 25 years, and is renowned for her commitment – at the Copenhagen climate conference in 2009 she was said to have slept overnight in a cupboard in the conference centre as the talks dragged on.

Reed is leading the UK’s negotiations on biodiversity in Cali, Colombia. He said: “We cannot address the nature and climate crises without coordinated global action. That is why we have appointed Ruth as our special representative for nature – a landmark first – who will champion our ambition to put climate and nature at the heart of our foreign policy.”

He added: “We depend on nature in every aspect of our lives – it underpins our economy, health and society – and yet progress to restore our wildlife and habitats has been too slow. Ruth’s extensive knowledge and expertise will be vital to help us deliver on our commitments to put nature on the road to recovery.”

Lammy has also promised to put the climate and nature protection at the heart of the UK’s foreign policy, as he views the environmental crises as threats to national security. Keir Starmer, the prime minister, has also set out his intention for the UK to lead in these areas, citing the climate in his speech to the UN general assembly last month.

“We are returning the UK to responsible global leadership,” he told fellow heads of government. “Because it is right, but also because it is plainly in our self-interest.”

Davis said: “The government has recognised that the nature crisis is of equal gravity to the climate crisis, and that we cannot tackle one without addressing the other. Ecosystems and the species they support are essential to maintain food security, reduce health risks and manage the impacts of rising global temperatures.”

Her appointment follows that of Rachel Kyte, formerly the top climate official at the World Bank, to the role of climate envoy, a post that was scrapped under the Conservative government. That appointment was criticised as Kyte also holds a position on an advisory board to a charitable foundation funded by a financial investment firm that made a £4m donation to Labour before the election.

Kyte was not involved in that decision, and many prominent environmental experts leaped to her defence. Nicholas Stern, the economist, told the Guardian: “Rachel was on the board of the philanthropic foundation and not the company, and she was very well equipped to advise that foundation. No conflict of interest.”

The Guardian understands that Davis will not hold any other external roles.

Davis beat a strong field of candidates for the new role of nature envoy. Names spoken of in relation to the post included Tanya Steele, the chief executive of WWF UK; Matthew Gould, the chief executive of the Zoological Society of London; and Tony Juniper, the chair of Natural England.

Leading voices in green campaigning hailed Davis’s appointment. Edward Davey, the head of the UK office of the World Resources Institute thinktank, said: “Ruth Davis is the environmentalist’s environmentalist, and the best of us: profoundly knowledgeable, deeply committed, a person of fearless integrity, and entirely selfless. She will be a wonderful nature envoy and is a brilliant appointment.”

Zac Goldsmith, the Conservative former minister, said: “I worked with Ruth as a minister and was always impressed by her knowledge and commitment. She will be a real asset to the new government.”

Oscar Soria, the director of the Common Initiative, a thinktank specialising in global environmental policy, said: “Ruth’s name means: a compassionate friend. The UK is now appointing a big heart and a clear mind, and that’s good news for the world.

“Her deep understanding of global contexts, paired with a diplomatic touch that bridges cultures and countries, sets her apart. In a world needing both global insight and local action, Ruth thrives in complexity. Her intelligence is matched by an often overlooked quality: compassion. At a time when the world needs thoughtful, caring leadership, Ruth is the person to guide the UK with empathy and respect, ensuring no path is left unexplored in the fight for biodiversity.”

The UN biodiversity conference Cop16 in Cali begins on Monday. At the summit, governments will examine progress towards meeting this decade’s UN targets to halt biodiversity loss, which include protecting 30% of land and sea for nature and repurposing $500bn (£380bn) of environmentally harmful subsidies.

Giant orange pumpkins with ghoulish grins have become a Halloween doorstep tradition but this year trick-or-treaters may be greeted with even spookier green-tinged jack-o-lanterns after a nightmare season for growers.

In Asda, pumpkin displays have signs telling shoppers “don’t worry if I’m slightly green, I will ripen at home and turn orange”.

With shoppers used to increasingly super-sized pumpkins, reviewers on supermarket websites also complain that this year’s batch don’t measure up.

“We had a cold, wet spring so the initial plantings on some farms failed,” said Julian Marks, the chief executive of the producer Barfoots. When the weather improved the fields were replanted but some did not have enough time to turn orange, he said. “There is quite a lot of green out there.”

“Right from the start of the season the weather has been not conducive to a bountiful harvest,” Marks continued. “In terms of ripeness, they’re perfectly good pumpkins and they’ll carve and look wonderful in the dark with a candle stuck in the middle, but they might not be 100% orange.”

It has been a year to forget for all farmers, not just those in the pumpkin business. England is said to have had its second-worst harvest on record after heavy rain last winter hit production of key crops, including wheat and oats.

Marks said Barfoots, which supplies 1m pumpkins to retailers, “scraped by” against the odds. “We’ve had a good crop but no surplus. We’ve had one or two shortages of speciality pumpkins but in general we’ve managed to meet demand.”

While it is usually zombies, witches and ghouls causing sleepless nights at Halloween, you could add a new slimy foe this year, with National Trust gardeners blaming the “slug army”, which thrived in the inclement weather, for disappointing pumpkin hauls.

The Royal Horticultural Society gardeners had a similar story. “Our pumpkin and squash harvest are below expectation by probably about 25% compared with other years,” said Peter Adams, a horticulturist at RHS Garden Rosemoor in Devon.

“The overall size of many of the pumpkins and squashes is considerably down on other years,” he said, citing “poorer than average light levels, fewer sunny days, and colder temperatures early on in the season”.

Jack Ward, the chief executive of the British Growers Association, said the rain in the early part of the growing season had caused problems for a lot of growers. “Pumpkins don’t like those conditions … slugs are a big problem too,” he said. “It’s by no means universal. Some people have had a good run but I think the general feedback is that it has been a difficult season.”

The grim dispatches from pumpkin patches have fuelled fears of shortages as the countdown to Halloween begins in earnest, but Tesco, the UK’s biggest retailer, has plenty, and price competition between the supermarkets is as fierce as ever.

“There’s a disconnect between what consumers are asked to pay and availability,” said Ward. “Retailers like to have a sort of consistent pricing and quite often, the price that consumers pay isn’t a true reflection of what it cost to put it on the shelf.”

If the shelves are bare when you get there, you could “cherish” a turnip instead, as Thérèse Coffey, the then environment secretary, suggested during last year’s salad shortage. You may even remember a time when turnips were the Halloween decoration of choice.

In previous years, English Heritage has revived this old practice, decorating its sites with the root vegetable, so should aficionados of the autumn celebration be carving turnips?

Dr Michael Carter, an English Heritage historian, said holiday traditions were always being reinvented. If I wanted to avoid getting a callus on my hand, it “would most definitely be a pumpkin”, he said, but opting for a turnip would “speak to older, indigenous traditions”.

“Carving a turnip would definitely turn it into a way of connecting with my childhood,” he said. “So much of what we think about calendar festivals as adults is nostalgia and connecting with our own past, as much as deeper trends in history.”