About 8,000 North Korean soldiers are stationed in Russia on the border with Ukraine, the US secretary of state has said, warning that Moscow is preparing to deploy those troops into combat “in the coming days”.

Antony Blinken said the US believed that North Korea had sent 10,000 troops to Russia in total, deploying them first to training bases in the far east before sending the vast majority to the Kursk region on the border with Ukraine.

Blinken told a press conference that the North Korean troops had received Russian training in “artillery, UAVs [unmanned aerial vehicles], basic infantry operations, including trench clearing, indicating that they fully intend to use these forces in frontline operations”.

The announcement was the clearest statement yet from the US that it anticipated the first large-scale deployment of foreign troops into the Russia-Ukraine war since Moscow’s full-scale invasion in February 2022.

The deployment could expand the largest land war in Europe since the second world war into a multi-region conflict, tying in the rising tensions in the Korean peninsula between North and South Korea.

“One of the reasons that Russia is turning to these North Korean troops is that it’s desperate,” Blinken said during the press conference as he met South Korea’s foreign and defence ministers in Washington. “Putin has been throwing more and more Russians into a meat grinder of his own making in Ukraine. Now he’s turning to North Korean troops, and that is a clear sign of weakness.”

Blinken’s comments came hours after North Korea test-fired an intercontinental ballistic missile, highlighting a potential advancement in its missile technology as questions continue over a potential agreement between Vladimir Putin and Kim Jong-un for North Korea’s support in the war against Ukraine in exchange for Russian military or space technology.

North Korea last test-fired a ballistic missile in December 2023. Thursday’s launch flew for 86 minutes – the longest recorded flight time to date – and may indicate that the country was seeking to develop missiles that could carry larger payloads for a potential strike against its enemies in the west.

US officials from the White House, state department and Pentagon have all warned Russia and North Korea against deploying North Korean troops in battle. If they did, Blinken said, they would become a “legitimate military target”.

Speaking before a UN security council meeting this week, the US envoy to the UN said that if Pyongyang’s forces “enter Ukraine in support of Russia, they will surely return in body bags”.

Ukraine’s president had earlier warned that North Korean troops could join the fight against Ukraine “within days” and that the deployment was meant to be a test of the US’s and South Korea’s responses.

Speaking in an interview on Wednesday with the South Korean radio outlet KBS, Volodymyr Zelenskyy said North Korean troops had not yet engaged in direct combat with Ukrainian forces but were preparing to be deployed.

Zelenskyy said he believed Putin wanted to deploy foreign troops in order to minimise casualties among Russian troops and that Russia would “station North Korean troops on the frontlines, and will sacrifice them more than Russian troops”.

Asked when that may be, he said: “I believe this will occur not within months, but within days.”

He also suggested North Korea could send more troops to Russia based upon how the US and South Korea respond.

“With this deployment of North Korean troops, Putin is currently testing the response of South Korea and the Nato member nations,” Zelenskyy said in the interview from the city of Uzhhorod. “After gauging their response, he will determine whether to expand the deployment.”

The Pentagon and South Korea’s defence minister issued a warning to Pyongyang on Thursday to remove their troops from Russia, with the US warning that North Korean troops would become “legitimate military targets” if they fought against Ukraine directly.

North Korean troops would be “co-belligerents, and you have every reason to believe that … they will be killed and wounded as a result of battle,” the US secretary of defence, Lloyd Austin, said on Wednesday.

The EU’s greenhouse gas emissions fell 8% last year, the European Environment Agency (EEA) has found, as the continent continues to close down coal-fired power plants and make more electricity from sun and wind.

The steep drop in planet-heating pollution in 2023 is close to the fall recorded in Europe at the start of the Covid-19 pandemic, when travel restrictions grounded planes and shuttered factories.

The findings come as scientists say that the climate crisis acted to strengthen the furious downpours that inundated southern and eastern Spain on Tuesday, killing more than 150 people.

“The impact of climate change is accelerating,” said the EEA’s executive director, Leena Ylä-Mononen. “This leaves us no choice but to strengthen our resilience to climate change and reduce greenhouse gas emissions.”

The report found the EU’s greenhouse gas emissions were now 37% below their levels in 1990.

The European Commission, which released a separate progress report on Tuesday, described the reduction as “very encouraging”. It said it “reinforced confidence” in the EU’s ability to meet its target of cutting emissions 55% by 2030.

But the EEA found there was still a gap to close. Current policies from member states are expected to reduce emissions by 43% by 2030 from their 1990 levels. Planned measures that have not yet been rolled out would bring this up to 49% – still leaving a gap of six percentage points.

“The significant emissions reductions in 2023 mark a major step towards the overall 2030 climate target,” the authors wrote. But “an acceleration of efforts will be needed”, they added.

The average European has done more than most to clog the atmosphere with planet-heating emissions, but efforts in recent decades to cut pollution have narrowed the gap. The report found the average European emitted 7.26 tonnes of greenhouse gas pollution in 2023, slightly more than the global average of 6.59 tonnes.

The biggest drop in pollution last year came from the energy sector, the EEA found, as a result of the rapid rollout of renewable energy, which has accelerated the shift away from fossil fuels.

Industrial emissions fell 6%, as some factories grew more efficient and others cut production, while similar progress was observed in the building sector.

Progress in other sectors was well below the levels needed to hit net zero emissions by 2050. Emissions from farms fell by just 2% last year, while the transport sector’s emissions fell by just 1%.

The findings come as diplomats prepare for the Cop29 climate summit in Azerbaijan in November, with the aim of speeding up and paying for the shift to a clean economy.

Wopke Hoekstra, the EU’s climate commissioner, said the EU had shown it was possible to “take climate action and invest in growing our economy at the same time”.

He said: “Sadly, the report also shows that our work must continue, at home and abroad, as we are seeing the harm that climate change is causing our citizens.”

A separate analysis on the climate news website Carbon Brief on Tuesday suggested that emissions in China, the world’s biggest emitter, were nearing a peak. It found emissions stayed steady in the third quarter of this year, and would fall overall in 2024 if there were a drop of at least 2% in the final quarter. The country’s official plan is to peak before 2030.

Lauri Myllyvirta from the Centre for Research on Energy and Clean Air wrote: “While the rapid clean-energy growth points to the possibility of China’s emissions peaking imminently, policymakers are still setting an expectation that emissions will increase until the end of the decade and plateau or fall very gradually thereafter.”

A commuter car park in Essex is to be one of the first test cases of whether the government will enforce new legislation aimed at protecting national parks and landscapes in England.

Dedham Vale is a designated “national landscape” on the border of Essex and Suffolk, home to increasingly rare species including hazel dormice and hedgehogs. Within it is Manningtree station, where the train operator Greater Anglia built an extension to the car park to cope with increased traffic.

Campaigners say the 200-metre long wall built as part of the extension inhibits public access to St Edmund Way, an ancient pilgrimage path, generates light pollution and threatens habitats. They are now locked in dispute with the planning inspectorate over whether the development should be allowed to stay and have applied for a judicial review, which is likely to be heard early next year.

The seemingly localised case has much wider implications because it will be a test for new legislation that requires local authorities and all other public bodies in England to “seek to further” the aims of protecting landscapes in every decision taken that could have an impact on those landscapes.

Campaigners want to use this duty, contained in section 245 of the Levelling-up and Regeneration Act 2023, to force public bodies to take much greater action to improve national parks and protected landscapes, formerly known as areas of outstanding national beauty.

In the case of Dedham Vale, the local preservation society said the legislation, which came into force late last year, should mean the end of the 200-metre wall, arguing that the government’s planning inspectorate did not take into account the new duties when deciding the extension to the car park could stay.

Charles Clover, the chair of the Dedham Vale Society, and a longstanding environmental campaigner and writer, said: “There are shades of Mr Bates and the Post Office about this. If the protections of national parks and national landscapes are to be held too lightly by officialdom, we will fight to our limits to have them reaffirmed.”

Dedham Vale is not an isolated case – the widening of the A66 in the Pennines, and the M3 junction project near Winchester, Hampshire, are also being objected to on similar grounds.

Rose O’Neill, the chief executive of the Campaign for National Parks, said: “[The change in regulations] is an absolute game-changer, requiring all public bodies that own land or make decisions affecting protected landscapes to take action to conserve and enhance wildlife and natural beauty.”

O’Neill said she was worried the legislation was not being enforced and that the Labour government could try to ignore this. “There’s now multiple examples of public bodies ignoring the law,” she said. “They must know the law has changed, but they’re happy to keep their heads in the sand. This wilful blindness is vandalising the UK’s most iconic and nature-rich landscapes.”

O’Neill added: “The government needs to ensure compliance right now. It urgently needs to make a statement and bring forward guidance and regulations to give the legislation teeth and ensure all public bodies redouble their efforts to enhance national parks and landscapes, and ensure they are protected from harm.”

A government spokesperson said: “Progress to restore nature has been too slow and our precious national parks and national landscapes are in decline. That is why we will protect our most beautiful landscapes, create more nature-rich habitats and help our national parks become wilder, greener and more accessible to all as we deliver our commitment to protect 30% of land for nature by 2030.”

Nearly 20 years ago, the British mathematician Clive Humby coined a snappy phrase that has turned into a platitude: “data is the new oil”. He wasn’t wrong. We have an insatiable appetite for data, we can’t stop generating it, and, just like oil, it’s turning out to be bad news for the environment.

So the Guardian set me a challenge: to try to give a sense of how much data an average person uses in a day, and what the carbon footprint of normal online activity might be. To do that, I tried to tot up the sorts of things I and millions of others do every day, and how that tracks back through the melange of messaging services, social networks, applications and tools, to the datacentres that keep our digital lives going.

My own carbon tally gets off to a bad start, and it is not even my fault. The email from my editor asking me to try to quantify quite how much data a single person uses in a day is itself contributing to my footprint. If the editor took 10 minutes to write the email – likely, given it was quite detailed – and it took me three minutes to read, and if it was sent from a laptop and received on one, then we have generated 17g of carbon dioxide (CO₂) emissions already, according to estimates by Mike Berners-Lee, a professor at Lancaster University’s Environment Centre, and the author of How Bad are Bananas? The Carbon Footprint of Everything.

My frantic emails to people asking to speak to them for this story pump out more carbon at a prodigious rate. And though 17g of CO₂ is insignificant compared with the 384.2m tonnes of net emissions the UK as a whole is responsible for each year, it all adds up.

All those emails and videos and games don’t just appear on our screens by magic. Everything we do digitally involves the vast transfer of data through the internet from one place to another, brokered through datacentres. Datacentres are vast premises full of computer servers that store data. The idea behind them is to reduce what the data industry calls “latency”, the time between you typing in a web address or clicking on an app button, and the content you are requesting being delivered to you. Everything on the internet, every link you click, every video you watch, is physically stored in a datacentre somewhere.

Datacentres are big business, and vast numbers of them are being built around the world. In the UK, Amazon has just announced plans to invest £8bn over the next five years building new datacentres and maintaining those it already has, “supporting 14,000 jobs annually”. That comes on top of £3bn already spent in the UK by Amazon’s cloud computing arm since 2020. Google is spending $1bn on a new centre at a 133,500 sq metre (33-acre) site in Hertfordshire, and at the end of last year Microsoft committed to £2.5bn of investment in the next three years, more than doubling its datacentre footprint in this country.

The reason for this is simple: demand is increasing at alarming rates. Americans used 100tn megabytes of wireless data in 2023, a record-breaking increase of 36% on the previous year – that’s enough to download Candy Crush Saga 265bn times.

It is a lot of data, and a lot of energy is required to serve that data to us, plus a lot of water to keep all those servers cool. In fact, Ireland, the Netherlands and Singapore are so worried about the energy impact of datacentres that they have imposed moratoria on new developments. When Google announced its environmental impact earlier this year, it revealed its own greenhouse gas emissions had risen 48% in the last five years, and 13% in the last 12 months, largely driven by increased datacentre demand to service its AI needs. Now big tech companies have come up with another solution to try to solve the looming energy crisis: their own nuclear power plants. Microsoft has struck a deal to recommission the Three Mile Island site in Pennsylvania, Google recently announced plans to build six or seven new small reactors to meet its anticipated energy needs. There’s no way round it: a steady stream of environmental harm is coming from our everyday actions – activities that we often don’t think about in relation to the target of limiting global heating to below 1.5C.

“You will run into this pretty much anywhere during the day,” says Alex de Vries, who researches the carbon footprint of our day-to-day lives at the Vrije Universiteit Amsterdam in the Netherlands. “Digital applications are so deeply embedded in our lives nowadays, it’s really hard to avoid. The thing is, when you’re using them, it’s not like you have something popping up in the screen telling you, like: ‘Hey, be aware, this activity has this carbon footprint.’”

De Vries also runs the Digiconomist website, which tries to track – where possible – the environmental impact of these things. That “where possible” is an important caveat. “It’s incredibly hard to figure out that information,” says de Vries.

In the absence of reliable figures from the companies themselves, educated guesses are often all we can rely on. Case in point: estimates of the proportion of world energy use that the internet makes up range from 3.7% to 10%, depending on who is counting. One estimate by Zero Waste Scotland suggests all our online activity generates an average of 8.62kg of CO₂ a week (about 448kg a year), or about 30 miles in an average-sized petrol car. But a German estimate (which also includes the emissions created by the production digital devices themselves) says we expend around twice that, roughly 850kg a year.

People struggle with two key problems when trying to wrap their heads around their data usage and resultant carbon impact, says De Vries. One: everything is digital, and therefore not tangible. “If you’re holding a pen and a piece of paper, you can get some idea of what might be necessary to make this product,” he says. “But if you’re using a digital application, what’s really going into that to make all of that happen? A lot of people simply will have no clue what that looks like.”

The other issue is that the tech companies are really good at making things work. “You probably don’t even know what is in [an application],” says De Vries. You press the button, and the Netflix series starts.

Companies such as Netflix are disarmingly honest about their data usage: if you keep your video quality on “low”, you use a paltry 300MB an hour of data on a streaming service such as Netflix. If you want to watch things in HD, though, you ramp up to 3GB an hour when looking at the most detailed scenes. If you are a movie connoisseur, your 4K streaming uses up to 7GB an hour.

But while few would argue we should spend less time in front of streaming services, the environmental impact of all that binge-watching appears to be comparatively low. A 2020 analysis by the International Energy Agency (IEA) found that watching an hour of Netflix was equivalent to boiling a kettle once: about 36g of CO₂.

There are other variables to take into account, though: the energy consumption of the device you are watching on, for example (Netflix says 70% of its viewers use televisions, which are more energy-hungry than mobile phones); or how the electricity you are using is generated (nuclear or wind is less carbon-emitting than coal or gas).

If you want to gossip about the latest episode with your friends, that also comes with an environmental toll. The average WhatsApp group chat uses 2.35kg of CO₂ a week, Zero Waste Scotland calculated. (To blunt the impact slightly, rely more on emojis – which are stored locally on your device – than reaction gifs, which have to be downloaded afresh from datacentres.) Listening to music online also comes at an environmental cost, although it is estimated that you can stream music for five hours before you will emit more CO2 – 288g – than is involved in making a CD in a case. Like many tech companies, Spotify has committed to reaching net zero emissions, in its case, by 2030.

Big tech companies buy carbon credits and offsets to try to mitigate the impact of their activity, but it’s often seen as a poor attempt at atonement for the environmental impact they cause. There are also questions about the extent to which firms’ reported datacentre emissions are capturing the whole picture. A recent Guardian analysis found that real emissions between 2020 and 2022 from datacentres owned by the four big tech companies, Google, Microsoft, Meta and Apple, were likely to be 662% higher than officially reported.

The tech industry’s warm embrace of generative AI has complicated things even further. It is becoming increasingly difficult to avoid. Type certain searches into Google and you will be given an “AI overview”, as Google calls them, which summarises key information from the results the search engine finds and presents it in a simple set of bullet points, alongside associated links. And you can’t turn it off. “AI Overviews are a core Google Search feature,” the company says.

“Generative AI hasn’t necessarily added very many new use cases,” says Sasha Luccioni, AI and climate lead at AI company Hugging Face. “It’s adding more compute and more environmental impacts to existing use cases.” The problem is that we don’t fully know how much. “None of the corporates, and none of the proprietary models, have published any numbers,” she says. De Vries’s research suggests that AI-powered search results use 10 times the power that non-AI searches do.

All this is before you get into the conscious use of generative AI tools such as ChatGPT or Anthropic’s Claude chatbot – where you are going to their websites or opening their apps, and taking part. Here, we are also in the dark about how much data, and therefore how much energy and water, generative AI uses. The best information we have is from informed third-party estimates: training GPT-3, a precursor to the current model, used an estimated 5.4m litres of water, according to one academic study, and produced as much CO₂ as would be generated by flying between New York and San Francisco 550 times.

I recently published a book on AI and as part of that, I have been touring and giving talks about AI’s impact on our world. In my favourite set of slides that I present there is a party trick. To highlight concerns around copyright in generative AI, I ask ChatGPT’s image generator, Dall-E, to produce a depiction of whichever place I’m in, in the style of Vincent van Gogh’s The Starry Night.

The gimmick always gets a laugh and serves its purpose: it shows how often the AI system has seen that painting by the ability to mimic its brushstrokes. But I always feel guilty. Because each time I do that, whether in Chipping Campden or Vilnius, I’m using data. About halfway through my book tour, I started adding a couple of slides immediately afterwards on the environmental impact of AI.

So besides stopping generating bootleg Van Goghs, what should those of us conscious about our environmental footprint do? Luccioni advocates for “digital sobriety”: being mindful about how we use AI. “You don’t need to be using these new AI tools for everything,” she says. “There are applications that are useful, but there’s a lot of cases where you really don’t need them.” The same approach holds true for everything digital: think twice, text once.

Your data diet

Estimating how much data your daily activities use is an art not a science, but here are best estimates of how much you are gobbling up online.

• Listening to a podcast: 20-100MB an hour

• Watching Netflix: 3GB an hour at HD quality

• Online shopping: Consider the data size of any images you browse, which can be big, before even thinking of the environmental impact of your delivery

• WhatsApp text message: 1-5KB a message, on average

• WhatsApp voice call: 400KB-1MB a minute

• WhatsApp video call: 2.5-15MB a minute

• Average pre-AI Google search: 500KB for a text-based search

• Average post-AI Google search: No one knows …

• Sending an email: Depends on the size of the message, but about 75KB on average

• Sending an email with photo attachment: As above, plus the size of the attachment

• Downloading an album on Spotify: Depends on your audio quality, but around 72MB for an hour-long album

• Playing a game of Fortnite: Between 45 and 100MB an hour

They call it cloud milking, a zero-energy technique to extract water from fog that is revolutionising the recovery of forests devastated by fire and drought.

The idea began as a pilot project in the Canary Islands. The plan was to exploit the moisture-laden “sea of clouds” that hangs over the region in order to aid reforestation, and has since been extended to several other countries to produce drinking water, and to irrigate crops.

“In recent year the Canaries have undergone a severe process of desertification and we’ve lost a lot of forest through agriculture. And then in 2007 and 2009, as a result of climate change, there were major fires in forested areas that are normally wet,” said Gustavo Viera, the technical director of the publicly-funded project in the Canaries.

Viera said that after the devastating fires they sought ways to deliver water to remote, mountainous areas without creating infrastructure, or using fossil fuels to extract ground water from deep wells.

The project, named Life Nieblas (niebla is the Spanish word for fog) began, backed by the EU, intended to mimic the way that the leaves of the local species of laurel trees capture water droplets from fog, by using sheets of plastic mesh erected in the path of the wind. As the wind blows fog through the mesh, water droplets collect and fall into the containers below, which is used to irrigate new saplings until they have sufficient leaves to capture the water themselves.

However, the wind, though vital to the original structure, proved a problem as it destroys all but the smallest structures.

“We needed to solve the problem of the fragility of the netting while minimising the environmental impact,” Viera said. “We developed a system that imitates pine needles, which are very good for capturing water while also letting the air pass through, and it’s a system that can easily be replicated in other locations and that’s also easy to transport to where it’s needed.”

In the new models, water condenses on the fine metal fronds of the structures, replicating the way conifers collect water from the atmosphere.

The water is discharged automatically without any energy supply or CO₂ emissions and no machinery is used to transport it from one place to another. No electrical systems are used for irrigation and the water footprint is also reduced as no aquifers or rivers are exploited. The only power needed is for building the collectors and getting them in place.

A slightly different technique is also being applied to reforest an abandoned quarry in Garraf, a rugged area south of Barcelona.

“Here we are using individual water collectors of the type used to keep herbivores from eating young plants,” said Vicenç Carabassa, the project’s head scientist, who works for the Centre for Ecological Research and Forestry Applications (CREAF), a public research institute at the Autonomous University of Barcelona.

“They collect rain and the heavy dew that falls on summer mornings and also provide shade.”

Carabassa pointed out that not every type of fog is suitable because some don’t have a high enough moisture content. The ideal fog is orographic or mountain fog, which exists in many Mediterranean regions and also in northern Portugal.

“The Canaries are the perfect laboratory to develop these techniques,” said Carabassa. “But there are other areas where the conditions are optimal and where there is a tradition of water capture from fog, such as Chile and Morocco.”

The method is now being used to supply drinking water and water for irrigation to the Chilean coastal village of Chungungo in Coquimbo province, while in the Cape Verde archipelago Life Nieblas collectors, combined with locally-made wooden structures, are providing 1,000 litres of water per day, which is used to irrigate crops and water livestock.

All the information necessary to create fog collectors is freely available to the public on the project’s website, and Viera said they’ve had many enquiries.

The benefits are palpable. In the Barranco del Andén ravine in Gran Canaria, 35.8 hectares (96 acres) have been reforested and 15,000 trees of various laurel species have been planted, with a survival rate of 86%, double the figure of traditional reforestation.

“We have recovered the forest’s potential to capture atmospheric carbon and estimate that we have captured around 175 tonnes of CO₂ per year,” Viera said.

The Life Nieblas project saves not only in fossil energy consumption and CO₂, but it is also cheaper and uses less water than traditional reforestation systems.

“We’re living with drought throughout the Mediterranean and also in the Canaries and now every drop of water counts,” said Carabassa, adding that we have to learn to live with much less water.

“This technique is never going to be an alternative to a desalination plant but in remote areas where water supply is difficult and expensive this can be a real alternative.”

With less than a week to go until the 2024 election, more than 57.5 million Americans have already voted, according to the Election Lab at the University of Florida. The number represents more than a third of the total turnout for the 2020 elections – it is hard to say what it means, as 2020 saw a high number of mail-in votes because of the Covid pandemic, but turnout in some states indicates that the Republican push for supporters to vote early is working.

Dressed in an orange hi-vis vest after a campaign stunt in a garbage truck, Republican nominee Donald Trump used a rally in Green Bay, Wisconsin, to take aim at the Democrats over Joe Biden’s “garbage” comments, thanked sanitation workers and promised to protect women “whether they like it or not”.

Elsewhere in Wisconsin, Kamala Harris appealed to first-time voters, for whom she said the issues of climate change, gun control, and abortion access are “not political. This is your lived experience.” She was speaking shortly after a new CNN poll showed her six points ahead of Trump in the state.

Here’s what else happened on Wednesday:

Kamala Harris election news and updates

• Harris spoke in Harrisburg, the Pennsylvania state capital, which is in one of the few counties that voted for Joe Biden in 2020. Polls show a tied race in Pennsylvania, which both campaigns are competing fiercely for. The path to winning 270 electoral votes is much more difficult for the candidate who loses Pennsylvania. Harris did not mention the racist remark about Puerto Rico made by a comedian at Trump’s Madison Square Garden rally on Sunday, but the state’s sizeable Latino and Puerto Rican population could be a decisive voting bloc.

• The former Republican governor of California Arnold Schwarzenegger has announced that he is backing Harris in next week’s election. In a long post on X, Schwarzenegger, 77, said that while he doesn’t “really do endorsements”, he felt compelled to formally endorse Harris and her pick for vice-president, Tim Walz.

• In an op-ed for the Guardian, Vermont Senator Bernie Sanders addressed progressives’ concerns about voting for Harris given the Biden administration’s stance on Israel’s war on Gaza. “I understand that there are millions of Americans who disagree with Joe Biden and Kamala Harris on the terrible war in Gaza. I am one of them,” he writes, adding that “on this issue, Donald Trump and his rightwing friends are worse.”

Donald Trump election news and updates

• Before his Green Bay rally, refused to apologise for the comments made about Puerto Rico at his Madison Square Garden rally, instead repeating his assertion that he did not know who the comedian was or how he got booked. “He’s a comedian, what can I tell you? I know nothing about him. I don’t know why he’s there.”

• A Pennsylvania judge on Wednesday sided with Trump’s campaign and agreed to extend an in-person voting option in suburban Philadelphia, where long lines on the final day led to complaints voters were being disfranchised by an unprepared election office.

• The House speaker, Mike Johnson, said there would be “massive” healthcare changes if Trump wins next Tuesday, including abolishing Obamacare. “Healthcare reform’s going to be a big part of the agenda,” Johnson, speaking at a rally in Pennsylvania on Monday, told the crowd. “When I say we’re going to have a very aggressive first 100 days agenda, we got a lot of things still on the table.”

Elsewhere on the campaign trail

• A Republican former congressional candidate was charged with stealing ballots during a test of a voting system in Madison county, Indiana, state police said on Tuesday. During the test on 3 October, which involved four voting machines and 136 candidate ballots marked for testing, officials discovered that two ballots were missing, according to the Indiana state police.

• A majority of voters in swing states do not believe Trump will accept defeat if he loses next week’s presidential election and fear that his supporters will turn to violence in an attempt to install him in power, a new poll suggests.

• The pace of US economic growth slowed over the summer but continued its two-year expansion, according to data released on Wednesday. US gross domestic product (GDP) – a broad measure of economic health – rose by 2.8% in the third quarter, short of economists’ expectations of 3.1%, and down from the previous quarter’s 3% reading.

• Officials in south-west Washington were able to salvage almost 500 damaged ballots from a ballot box that was set on fire on Monday in what officials have called an attack on democracy. An unknown number of ballots were destroyed when someone placed incendiary devices in a drop box in Vancouver, Washington, while three ballots were damaged in a fire at a box in nearby Portland, Oregon. Those fires and one other are linked, officials have said.

Read more about the 2024 US election:

I first encountered whale poop 30 years ago while I was working on a right whale research project. On one of my first days on the water, in the Bay of Fundy, in eastern Canada, we came upon a feeding male right whale with mud on its head – or bonnet – a sign that it had been feeding at the bottom of the bay. It had come up to breathe and rest.

Just before it dived in again, it released this enormous faecal plume.

There were gallons of poop in that water. It looked like red floating bricks. The smell was overwhelming. Some whale poop smells like brine and seawater, but with right whales, there’s a strong smell of sulphur.

If you get that poop on your clothes, you have to throw them away. You’re never going to wash it out.

I didn’t know it then, but that faecal plume would later spark my global search for whale faeces, from Iceland to Mexico, Alaska and Hawaii.

Since then, I’ve learned that whale faeces can tell us not only about the diet of a whale, but also about their hormones and reproductive status. It can reveal the whale’s stress levels, gut microbiome and genetic lineage. It even allows us to look at the level of mercury and pollution in the ocean – everything from microplastics to parasite loads.

Ambergris, which is formed in the hindgut of sperm whales when they digest squid beaks, is rare and extremely valuable. Since the 1970s, its trade has been restricted in many countries. But in the past, it was used to make perfumes, which were worn by Elizabeth I, Charles I and Casanova.

Whale faecal plumes can be neon green or bright red. At times, they sparkle with silver scales, like the sun glinting on the water. Every whale defecation is unique.

As for the smell, the poop of right whales is the strongest and foulest but I love the smell now.

It helped set the course for my research career. Two years after I saw whale poop for the first time, I took my first class in marine ecology and learned about one of the most important processes in the ocean, especially in carbon sequestration: the biological pump.

Phytoplankton, or algae, only grow near the surface of the ocean, where there is enough light for photosynthesis. Animals such as krill and copepods feed on it there and they are eaten by fish and even whales.

When this phytoplankton dies or is consumed, some of those nutrients are removed from the atmosphere and can sink to the bottom of the ocean. In this way, the biological pump plays an important role in moving carbon to the deep sea.

But I remember sitting there in class that day, thinking: there’s something missing here. Right whales often feed at depth and poop at the surface, so they’re likely bringing important nutrients like nitrogen, phosphorus and iron back up to the surface.

That set me off on the idea of a “whale pump” – which we’ve since discovered does the opposite of the biological pump. It pumps nutrients back up to the surface.

These nutrients can get picked up by phytoplankton and go through the entire ocean food chain. This is important because one of the justifications for whaling in Japan, Norway and Iceland is that whales eat “our fish”, therefore if there are too many whales, there will be a decline in fisheries.

The whale pump demonstrates it’s more complicated than that – and that the presence of whales in the ocean might actually increase fish populations.

As well as helping us to understand the state of the present ocean, whale poop gives us a glimpse into the past ocean and what it was like when there were hundreds of thousands of whales in the sea. If we can restore whales and the nutrient pathways that historically existed through their poop, it could help support more biodiversity in the ocean.

As told to Donna Ferguson

Governments risk another decade of failure on biodiversity loss, due to the slow implementation of an international agreement to halt the destruction of Earth’s ecosystems, experts have warned.

Less than two years ago, the world reached a historic agreement at the Cop15 summit in Montreal to stop the human-caused destruction of life on our planet. The deal included targets to protect 30% of the planet for nature by the end of the decade (30×30), reform $500bn (then £410bn) of environmentally damaging subsidies, and begin restoring 30% of the planet’s degraded ecosystems.

But as country representatives dig into their second week of negotiations at Cop16 in Cali, Colombia – their first meeting since Montreal – alarm is growing at the lack of concrete progress on any of the major targets they agreed upon. An increasing number of indicators show that governments are not on track. They still need to protect an area of land equivalent to the combined size of Brazil and Australia, and an expanse of sea larger than the Indian Ocean to meet the headline 30×30 target, according to a new UN report.

Weak progress on funding for nature and almost no progress on subsidy reform have also frustrated observers. At the time of publication, 158 countries are yet to submit formal plans on how they are going to meet the targets, according to Carbon Brief, missing their deadline this month ahead of the biodiversity summit in Cali, where governments are not likely to set a new deadline.

“Progress has been too slow. I think political prioritisation of nature is still too low. This is reflected by progress on the targets. Several target are very easy to measure: 30×30 has metrics on area and quality, finance has a dollar figure. We have new data on both that show we’re not on pace,” said Brian O’Donnell, director of the Campaign for Nature.

“This is a moment to demonstrate seriousness and build trust. On finance especially, it’s been disturbing at times to go to parties to ask for their path forward for finance and be treated as if we are asking for something new or unrealistic, as opposed to what they just agreed two years ago. To me, that is a reflection of not a true commitment to this,” he said.

The world has never met a target to stem the destruction of wildlife and life-sustaining ecosystems. Amid growing scientific warnings about the state of life on Earth, there has been a major push to make sure this decade is different, and that governments comply with targets designed to prevent wildlife extinctions, such as cuts to pesticides use and pollution.

Leading figures in conservation and science have raised concerns about the progress governments are making towards the targets in Cali. Martin Harper, CEO of Birdlife International, said meaningful action on commitments was vital.

“We cannot accept inaction as the new normal. This means more action to bolster efforts to recover threatened species, to protect and restore more land, fresh water and sea, and to transform our food, energy and industrial systems. We have five years to raise hundreds of billions of dollars. If we don’t see it materialise, I dread to think where we will be in 2030,” he said.

Inger Andersen, the UN environment head, said it was too early to say whether governments were not doing enough to meet the targets, underscoring that many were working hard. She said there had been signs of progress, but acknowledged more needed to be done.

“The world is working on it. Will we meet every single target by 2030? I hope. If we don’t, is that a catastrophe? No, but did we make a promise to each other that we are going to stretch and do the very best that we can,” she said. “We still have six years to go.”

Scientists at the nature summit in Cali said that the political pace was not matching the scale of the challenge. Nathalie Seddon, professor of biodiversity at University of Oxford, said much more was needed by the end of the decade.

“The biodiversity goals’ 2030 deadline exists for a reason: biodiverse, resilient ecosystems are the foundation of our economies and wellbeing. A bad outcome here isn’t just bad news for wildlife; it undermines food security, water quality, disaster resilience and economic stability. It worsens climate impacts of record-breaking heat, wildfires, floods and droughts,” she said.

Yadvinder Malhi, a professor of ecosystem science at the University of Oxford, said: “The very limited progress we’ve seen so far in the negotiations at Cop16 is insufficient to address the very real implications of getting this wrong. Biodiversity is continuing to decline at an alarming rate. I really hope that the crunch discussions this week yield those commitments, for the sake of a flourishing future for people and for our planet.”

A judge ordered all parties, including Elon Musk, to attend a court hearing in Philadelphia on Thursday in a lawsuit seeking to stop a political action committee controlled by the billionaire from awarding $1m to registered US voters in battleground states before the 5 November election.

The Philadelphia district attorney’s office filed the lawsuit on Monday. It called the giveaway by Musk’s America Pac, which backs Donald Trump, an “illegal lottery” that entices Pennsylvania residents to share personal data.

“It is further ordered that all parties must be present at the time of the hearing,” a judge wrote on Wednesday in an order with the county court of common pleas. The hearing in the case was moved up to Thursday morning from Friday.

A representative for America Pac did not immediately respond to a request for comment. Musk’s representatives have not responded to requests for comment.

Musk has promised to give $1m each day to someone who signs his online free-speech and gun-rights petition. Legal experts consulted by Reuters last week were divided on whether the giveaway violates federal laws that make it a crime to pay or offer to pay a person to register to vote. The justice department sent a letter to America Pac warning that the billionaire’s giveaways for registered voters who sign his petition may violate federal law, CNN reported last week.

Before an extremely tight presidential race between Trump and Kamala Harris, Pennsylvania is seen as a crucial swing state that could determine the outcome of the election. “Pennsylvania will be a decisive Republican victory,” Musk tweeted on Wednesday.

Josh Shapiro, Pennsylvania’s Democratic governor, said earlier this month that he thought law enforcement should look into the legality of the giveaway.

“I think there are real questions with how he is spending money in this race, how the dark money is flowing, not just into Pennsylvania, but apparently now into the pockets of Pennsylvanians,” Shapiro told NBC’s Meet the Press on 20 October. “That is deeply concerning.”

At a Musk town hall in Pittsburgh on 20 October, at which the Tesla CEO praised Trump and gave a giant $1m check to a woman in a red Trump T-shirt, audience members appeared unfazed by the criticism of the scheme, and said they admired Musk’s success as a businessman, and what they saw as his championing of free speech.

“I fear if Trump does not win, we are going to have a single-party state that is going to be like California, but actually worse,” Musk told the audience.

Musk has shared photographs of voters with $1m checks on X, the social media platform he owns. On Wednesday, the America Pac account announced that “Joshua from North Carolina earned $1M after signing our petition in support of the Constitution”.

The Trump campaign is broadly reliant on outside groups for canvassing voters, meaning the super Pac founded by Musk – the world’s richest man – plays an outsized role in what is expected to be a razor-thin election.