China has played down the risk of damage to its exports from Donald Trump’s tariffs, with an official saying the “sky won’t fall”, as stock markets rose amid signs of a retreat on electronics restrictions.

The US president claimed his strategy was working on Monday, with record levels of investment. Addressing reporters at the White House, he continued to threaten new tariffs on pharmaceutical goods.

As fears of a potential downturn continue to mount, Kevin Hassett, the director of the US national economic council, pushed back against warnings that a recession could take hold this year. “100% not,” he told Fox Business.

Leading tech stocks struggled for direction amid confusion over the Trump administration’s stance on key US imports including smartphones and semiconductors.

While it emerged that such electronic goods and components were exempt from the sweeping tariffs imposed this month, Trump and his officials have signaled they may not be spared for long.

“THE BEST DEFINITION OF INTELLIGENCE IS THE ABILITY TO PREDICT THE FUTURE!!!” Trump wrote on his Truth Social platform on Monday, as firms around the world struggled to keep up with the latest developments, let alone judge what might happen next.

Consumers are starting to feel the impact of the trade tensions. Sony increased the price of its PlayStation 5 by 25% in some markets in Europe, the Middle East, Africa and Oceania, citing “a challenging economic environment” as the video game industry reels from the impact of Trump’s tariffs.

China, meanwhile, has vowed to stand firm in the face of Trump’s tariffs. The world’s second-largest economy has diversified its trade away from the US in recent years, according to Lyu Daliang, a customs administration spokesperson, in comments reported by state-owned agency Xinhua.

Beijing has retaliated forcefully to Washington’s tariffs, with 125% levies on US imports against the US’s total of 145% border taxes on goods moving the other way. The trade war has prompted turmoil on financial markets since Trump first revealed tariffs on every country in the world on 2 April. Since then he has partly retreated on the highest levies on most trading partners for at least 90 days, but has doubled down in his spat with China.

The White House offered further relief over the weekend with an exemption from the steepest tariffs for electronics including smartphones, laptops and semiconductors. But Trump officials later appeared to walk that back with the commerce secretary, Howard Lutnick, saying such devices would be “included in the semiconductor tariffs which are coming in probably a month or two”.

Trump said on Sunday night on Truth Social that “NOBODY is getting ‘off the hook’,” highlighting that smartphones were still subject to 20% levies and suggesting they could still rise higher.

However, investors on Monday appeared unconvinced by Trump’s attempts to play down the retreat. Japan’s Nikkei gained 1.2% while Hong Kong’s Hang Seng rose by 2.2% and the Shanghai and Shenzhen exchanges climbed by 0.8% and 1.2%, respectively.

European stock market indices also jumped in opening trades, with London’s FTSE 100 up by 2.1%, Germany’s Dax up 2.6%, and France’s Cac 40 up 2.4%.

On Wall Street, the benchmark S&P 500 closed up close to 0.8% and the Dow Jones industrial average also gained 0.8%. The technology-focused Nasdaq Composite was 0.6% higher.

“The sky won’t fall” for Chinese exports, China’s Lyu said. “These efforts have not only supported our partners’ development but also enhanced our own resilience.”

The customs report also played up China’s “vast domestic market”, and said “the country will turn domestic certainty into a buffer against global volatility”. China has increasingly tried to stimulate private consumption.

China’s president, Xi Jinping, on Monday criticised the US tariffs, during a visit to Vietnam. Vietnam has in recent decades grown to become the eighth largest source of goods for US consumers, but it is facing the threat of 46% tariffs when Trump’s 90-day pause expires.

In an article in a Vietnamese newspaper, Xi said that a “trade war and tariff war will produce no winner, and protectionism will lead nowhere”.

A legal advocacy group on Monday asked the US court of international trade to block Donald Trump’s sweeping tariffs on foreign trading partners, arguing that the president overstepped his authority.

The lawsuit was filed by the Liberty Justice Center, a legal advocacy group, on behalf of five US businesses that import goods from countries targeted by the tariffs.

“No one person should have the power to impose taxes that have such vast global economic consequences,” Jeffrey Schwab, Liberty Justice Center’s senior counsel, said in a statement. “The Constitution gives the power to set tax rates – including tariffs – to Congress, not the President.”

The Liberty Justice Center is the litigation arm of the Illinois Policy Institute, a free market thinktank. It was instrumental in the supreme court case Janus v AFSCME in which it successfully fought to weaken public labor unions collective bargaining power.

According to the group’s statement, the tariffs case was filed on behalf of five owner-operated businesses who have been severely harmed by the tariffs. The businesses include a New York-based company specializing in the importation and distribution of wines and spirits, an e-commerce business specializing in the production and sale of sportfishing tackle, a company that manufactures ABS pipe in the United States using imported ABS resin from South Korea and Taiwan, a small business based in Virginia that makes educational electronic kits and musical instruments, and a Vermont-based brand of women’s cycling apparel.

Representatives of the White House did not immediately respond to an email seeking comment.

The Trump administration faces a similar lawsuit in Florida federal court, where a small business owner has asked a judge to block tariffs imposed on China.

The chief executive of Goldman Sachs, David Solomon, has warned that the chances of a US recession have “increased” in the wake of Donald Trump’s tariffs and that an escalating trade war poses “material risks” for US and global growth.

The Wall Street boss said the growing uncertainty over the fallout of US tariffs could spell trouble for companies and consumers and wreak havoc on the economy.

“We are entering the second quarter with a markedly different operating environment than earlier this year,” he told analysts during an earnings call.

“The prospect of a recession has increased, with growing indications that economic activity is slowing down around the world.”

The growing uncertainty had made it hard for Goldman clients to make important business decisions, he added. “This uncertainty around the path forward, and fears over the potentially escalating effects of a trade war, have created material risks to the US and global economy.”

Solomon’s warning came despite a temporary roll-back by Trump, who declared a 90-day pause on higher-band tariffs for countries outside China last week. The US president also announced plans to exclude some electronic products from steep reciprocal tariffs on Chinese goods.

Solomon said he was “encouraged by the US administration’s recent actions to pursue a more gradual policy process that allows for considered negotiations with many countries” but warned markets would continue to be volatile given that “how policy will evolve is still unknown”.

The banking boss tried to strike a diplomatic tone, saying that the “administration’s focus on trade barriers and strengthening the US competitive position is commendable”. However, he noted the US has been a beneficiary of global trade arrangements. “Few … benefited more from the post-second world war economic and financial order than the United States.”

“This doesn’t mean meaningful reform in certain areas is not warranted,” Solomon added.

His comments came as Goldman Sachs reported its best-ever quarter for equities trading, as the bank benefited from market turmoil triggered by Trump’s return to the Oval Office.

The Wall Street bank reported record revenues from its equity division in its first quarter, from January to the end of March, rising 27% compared with a year earlier to $4.2bn (£3.2bn). It helped push pre-tax profits up 8% in the first quarter to $5.6bn, a period that did not include the turmoil of Trump’s tariffs.

But prolonged volatility and uncertainty over the tariff fallout could dampen appetite for loans and deal-making, and delay stock market listings, in moves that could ultimately hit revenues for banks such as Goldman Sachs.

“So far, the business is performing very well and clients are very active,” Solomon said. “My guess is, over time, this level of uncertainty will come down.”

The UN’s trade and development arm, Unctad, is calling on Donald Trump to exempt the world’s poorest and smallest countries from “reciprocal” tariffs, or risk “serious economic harm”.

In a report published on Monday, Unctad identifies 28 nations the US president singled out for a higher tariff rate than the 10% baseline – despite each accounting for less than 0.1% of the US trade deficit.

These include Laos, which is expected to face a 48% tariff; Mauritius, on 40%; and Myanmar, to be hit with 45%, despite trying to recover from a devastating earthquake.

The White House shocked many developing countries with the punitive tariff rates announced this month.

Trump claimed rival economies had “looted, pillaged, raped, plundered” the US with unfair trade practices, and he wanted to create a level playing field.

Unctad said many of the countries targeted with high tariff rates were unlikely to be a threat to the world’s largest economy, given their small size and modest levels of exports.

The White House last week put the higher tariff rates on pause for 90 days, after unleashing chaos on world financial markets, leaving a 10% levy in place across the board.

But the administration’s formal position remains that the “reciprocal” tariff rates will come into force, subject to negotiations.

“The current 90-day pause presents an opportunity to reassess how small and vulnerable economies – including the least developed countries – are treated,” Unctad said.

“This is a critical moment to consider exempting them from tariffs that offer little to no advantage for US trade policy but risk causing serious economic harm.”

Unctad’s analysis said many of these economies were so small that they were likely to generate little demand for US exports, even if they lowered tariffs, as the White House appears to be demanding.

Malawi, facing 18% tariffs, bought just $27m of US exports last year; Mozambique, which faces 16% tariffs, $150m; Cambodia, set for 49% tariffs, $322m.

Unctad’s experts added that 36 of these small and poor countries were likely to generate less than 1% of total US tariff revenue, even if the US did not cut imports from them as the tariffs took effect.

Part of the logic of the tariff policy is meant to be to bring manufacturing jobs back to the US. But for several tiny countries, their key exports are agricultural commodities, for which the US is unlikely to be able to find substitutes elsewhere – let alone develop a domestic industry.

Unctad highlighted the $150m in vanilla imported from Madagascar, close to $800m in cocoa from Ivory Coast and $200m in cocoa from Ghana.

With Madagascar set to face 47% tariffs, for example, the report said the main impact on the US was likely to be higher prices for consumers.

Some of the countries hit by the 10% tariffs – and due to face higher rates when the pause is over – were previously beneficiaries of a US policy called the African Growth and Opportunity Act.

The scheme had been in place since 2000 and gave sub-Saharan African countries tariff-free access to US markets in order to encourage economic development. As many as 32 countries were eligible, before Trump’s announcement appeared to tear up the scheme.

Financial markets and manufacturers in developing countries are continuing to wrestle with the changeable nature of US trade policy.

Trump sowed fresh confusion over the weekend by appearing to revisit an announcement made on Friday, that some hi-tech goods, including laptops, would be exempt from tariffs.

In a post on his social media site Truth Social on Sunday, the president said no one was getting “off the hook”, and the administration would be investigating the “whole electronics supply chain”.

The president of El Salvador said in a meeting with Donald Trump in the White House on Monday that he would not order the return of a Maryland man who was deported in error to a Salvadorian mega-prison.

“The question is preposterous,” Nayib Bukele said in the Oval Office on Monday, where he was welcomed by Trump and spoke with the president and members of his cabinet. “How can I smuggle a terrorist into the United States? I’m not going to do it.”

He added: “I don’t have the power to return him to the United States,” and said he would not release the man, Kilmar Abrego García, into El Salvador either. “I’m not very fond of releasing terrorists into the country.”

The comments came a day after the Trump administration claimed it was not legally obligated to secure the return of Abrego García, despite the US supreme court ruling that the administration should “facilitate” bringing him back.

Lawyers for the justice department argued in court filings on Sunday that asking El Salvador to returnAbrego García from a notorious mega-prison should be considered “foreign relations”, and was therefore outside the scope of the courts.

The filing said “the federal courts have no authority to direct the Executive Branch to conduct foreign relations in a particular way, or engage with a foreign sovereign in a given manner,” adding: “That is the exclusive power of the president as the sole organ of the federal government in the field of international relations.”

Earlier this month, the Trump administration acknowledged that Abrego García, an immigrant from El Salvador who was living in Maryland with protected status, was deported to a prison in El Salvador on 15 March as a result of an “administrative error”. In 2019 an immigration judge had prohibited the federal government from deporting him.

When he was deported anyway, swept up in Trump’s effort to send hundreds of supposed gang members to El Salvador without due process, Abrego García’s wife and relatives filed a lawsuit against the Trump administration.

On 4 April a district judge, Paula Xinis, directed the administration to “facilitate and effectuate” his return. The supreme court upheld the directive on Thursday, and also instructed Xinis to clarify the order “with due regard for the deference owed to the executive branch in the conduct of foreign affairs”.

On Friday, Xinis said in a hearing that it was “extremely troubling” that the administration had failed to comply with a court order to provide details about Abrego García’s whereabouts and status. She ordered that it provide daily updates on efforts to facilitate his return.

On Saturday, the Trump administration confirmed Abrego García was alive and confined in El Salvador’s mega-prison, Cecot.

Then, on Sunday, the justice department said it interpreted the court’s order to “facilitate” Albrego García’s return as only requiring them to “remove any domestic obstacles that would otherwise impede the alien’s ability to return here”.

It added: “No other reading of ‘facilitate’ is tenable – or constitutional – here.”

In a separate court filing on Sunday, an official from Immigration and Customs Enforcement (Ice) said that the 2019 order preventing Abrego García’s removal to El Salvador was no longer valid, as a result of the administration’s allegation that he was a member of the MS-13 gang, “which is now a designated foreign terrorist organization”, the court filing states.

On Monday, during the Oval Office meeting between Trump and Bukele, Stephen Miller, White House homeland security adviser, repeated the claim that the 2019 order was no longer valid when Abrego García was deported, and said that bringing him back to the US would be “to kidnap a citizen of El Salvador and fly him back here”.

The attorney general, Pam Bondi, echoed that it was up to El Salvador “whether they want to return him”, not the US. Bondi also claimed the supreme court ruling meant that “if El Salvador wants to return him, we would ‘facilitate’ it, meaning provide a plane”.

But Miller also said: “No version of this ends with him living here.”

Six women – including the pop star Katy Perry and morning TV host Gayle King – safely completed a trip to the edge of outer space and back from a private Texas ranch on Monday morning on a rocket belonging to Jeff Bezos, the Amazon co-founder and commercial space flight entrepreneur.

The women, who also included Bezos’s fiancee, Lauren Sánchez, made the trip to the Kármán line – the internationally recognized boundary of space – to float about, weightlessly, in the rocket’s capsule for three minutes before returning to Earth.

“Yeah baby, go for launch,” a mission controller could be heard saying shortly before the single-engine New Shepard rocket blasted off on time, at 8.30am local time (9.30am ET and 13.30am GMT).

King’s longtime friend, the TV talkshow host Oprah Winfrey, was on hand in Texas for the launch. Winfrey remarked that, for King, “this is bigger than just going to space” and “more than just overcoming fear”.

“Life is about continuing into grow into the fullest expression of yourself,” Winfrey said.

The talkshow queen could later be seen rubbing her eyes as the rocket reached its maximum ascent velocity of 2,300mph – or Mach 3. A commentator remarked that the vehicle was rising into the atmosphere ahead of “a stream of steam”.

As the rocket reached its highest point, about 62 miles (100km) above the Earth, a passenger could be heard to exclaim: “Oh my goddess.” Another could be heard saying: “I love you, Jeff Bezos.”

On the way back down to Earth, more screaming could be heard. The capsule, detached from its booster, made a soft landing on the Texas plains, two miles from the launchpad.

“Congratulations, and welcome back to Earth,” the commentator said. “Everybody just as ecstatic to be back on Earth.”

Sánchez’s fiance later opened the hatch to welcome her back to Earth, followed by her crewmates. The billionaire greeted each with a hug and kiss.

Perry, holding a daisy, kissed the ground with King. In a post-flight interview, Sánchez said: “The Earth was so quiet but also really alive. We are all in this together, and some connected. It makes me just want to hug everybody.”

“I had to come back,” Sánchez, who is set to marry Bezos this summer in Venice, added tearfully. “I wanted to come back. I’m getting married.”

The alternative, she said, “would be a bummer for me”.

On her return to earth, Perry said Monday’s flight had been “the highest high”.

“It’s about surrender to the unknown, it’s trust, and this whole journey is about more than going to space,” Perry remarked. It’s up there with meditation.

“This is up there.”

She added: “What you’re doing is really finding the love for yourself. I’m really feeling that divine feminine right now.”

Perry, 40, said last week she was listening to an audiobook of Cosmos by Carl Sagan and reading a book on string theory in preparation for the ride.

“I’ve always been interested in astrophysics and interested in astronomy and astrology and the stars,” she told the Associated Press. “We are all made of stardust, and we all come from the stars.”

The pop star also said that she planned to channel “that feminine divine that I was born with” to prepare for the new experience.

Before liftoff, King – who co-hosts CBS Mornings – said she was approaching the rocket trip with trepidation. “I still get very uncomfortable when people say ‘astronaut’,” she said. “I in no means feel like an astronaut. They said: ‘But, Gayle, if you go to space, you’re an astronaut.”

The pair, along with the former Nasa rocket scientist Aisha Bowe, civil rights activist Amanda Nguyen and film producer Kerianne Flynn, traveled as the guests of Sánchez.

The flight was the 11th human flight for the New Shepard program, which has flown 52 people, including repeat astronauts, to the Kármán line.

Some critics have questioned whether the all-female trip is a moment of feminist progress since it comes as promotion for Bezos’s space tourism business that, in turn, is the marketing arm of Blue Origin’s commercial launch program.

The US actor Olivia Munn called the trip “a bit gluttonous” during a guest hosting appearance on Today with Jenna & Friends on CBS rival NBC.

“I know this is not the cool thing to say, but there are so many other things that are so important in the world right now,” Munn said. “What are you guys going to do up in space?”

Rory McIlroy has warned the members of Augusta National they will have to “wheel me out of here when I am 90 years old” after finally ending his wait to win the Masters. In doing so, McIlroy became just the sixth golfer in history to complete a career grand slam.

McIlroy has warned his fellow professionals that he already feels perfectly placed for more major wins after adding number five to his CV.

The Northern Irishman’s playoff win over Justin Rose preceded a reception with those who run the tournament. “I said I will be going to that champions dinner every Tuesday night and they are going to have to wheel me out of here when I am 90 years old,” he said. His victory earns him a lifetime Masters exemption.

The condensed nature of golf’s calendar means thoughts already flick towards the rest of this year’s majors. The US PGA Championship next month is at Quail Hollow, where McIlroy has won four times. The Open returns to Royal Portrush, in McIlroy’s homeland, in the summer.

“I really do think this is going to free me up in these things,” McIlroy said. “It has been a long time coming, over 10 years since winning a major championship. And especially doing this; getting the Masters, the career grand slam, the fifth major, getting all that out of the way.

“I think it will allow me to play with a lot more freedom. I can’t wait to go back to Portrush in July. There is still a lot of golf left to play this year. I am excited for all of it and excited with where my game is. I want to enjoy this right now but there is a lot to look forward to.”

McIlroy held a five-shot lead at one stage of the final round of the Masters. Rose’s excellent 66 earned sudden death after McIlroy missed a chance to win the Green Jacket on the final hole of regulation play.

“It feels like it has been a long time coming,” McIlroy said. “I had my first real chance of winning this 14 years ago. Every year coming to Augusta there has been a lot riding on it. Sometimes I handled that well, sometimes I didn’t. Thankfully I was able to get over the line.

“There were times in my life when I thought this was never going to happen, a few low points driving out of Magnolia Lane on Sunday nights. To finally get the job done is unbelievably satisfying. I don’t think it will sink in for a while. I persevered and was able to come out on top.”

A 10-year-old McIlroy spoke on television in Northern Ireland of winning every major. Now, 25 years on, the dream was fulfilled. “When you are 10 years old, you don’t really know what you are saying but there was something in there,” McIlroy said.

“I am incredibly fortunate, my mum and dad saw potential in me and did everything possible to try to let me fulfil that potential. This is as much theirs as it is mine.

“For my team, it is validation that the work we have been putting in is paying off. For my mum and dad, hopefully it doesn’t change anything. I hope they were proud of me before this and I hope they are proud of me now.

“As the years go by, you cherish more and more your time with them and for them to be able to see me do this means a great deal to me.”

The climate crisis has tripled the length of ocean heatwaves, a study has found, supercharging deadly storms and destroying critical ecosystems such as kelp forests and coral reefs.

Half of the marine heatwaves since 2000 would not have happened without global heating, which is caused by burning fossil fuels. The heatwaves have not only become more frequent but also more intense: 1C warmer on average, but much hotter in some places, the scientists said.

The research is the first comprehensive assessment of the impact of the climate crisis on heatwaves in the world’s oceans, and it reveals profound changes. Hotter oceans also soak up fewer of the carbon dioxide emissions that are driving temperatures up.

“Here in the Mediterranean, we have some marine heatwaves that are 5C hotter,” said Dr Marta Marcos at the Mediterranean Institute for Advanced Studies in Mallorca, Spain, who led the study. “It’s horrible when you go swimming. It looks like soup.”

As well as devastating underwater ecosystems such as sea grass meadows, Marcos said: “Warmer oceans provide more energy to the strong storms that affect people at the coast and inland.”

One disastrous example was the intense rainfall that caused catastrophic flooding in Libya in 2023, which killed 11,000 people. It was made up to 50 times more likely by global heating, which had raised temperatures in the Mediterranean by as much as 5.5C. That resulted in more water vapour and therefore more rain.

“The only solution is cutting the burning of fossil fuels. This is a very clear relationship,” said Marcos. “More than 90% of the extra heat [trapped by greenhouse gas emissions] is stored in the ocean. If you stop warming the atmosphere, you will stop warming the ocean.”

Recent major marine heatwaves include an exceptionally long event in the Pacific in 2014-15, which caused mass mortality among marine life. Intense heat hit the Tasman Sea in 2015-16 and record sea temperatures around the UK and in the Mediterranean Sea in 2023. Scientists had warned in 2019 that ocean heatwaves were increasing sharply, killing swathes of sea-life like “wildfires that take out huge areas of forest”.

Dr Zoe Jacobs at the UK’s National Oceanography Centre, who was not part of the study team, said: “Ocean heatwaves pose significant risks to society, with some individual events causing millions of dollars of losses due to impacts on the fishing, aquaculture and tourism industries. They have also been found to exacerbate heatwaves on land and have amplified extreme weather like hurricanes and storms.”

The study, published in the Proceedings of the National Academy of Sciences, built a model of sea surface temperatures since 1940 that removed the heating the climate crisis has caused. They then compared that with actual measurements from the oceans to show how global heating has pushed up temperatures. They focused on summer heatwaves, because they reach the highest temperatures and are therefore the most damaging.

The analysis revealed there were about 15 days of extreme heat a year at the ocean surface in the 1940s, but the figure had jumped to a global average of nearly 50 days a year. Some regions, including the Indian Ocean, the tropical Atlantic and the western Pacific have 80 heatwave days a year, ie one day in every five.

The seas in the tropics are already warm, so the extra heat tends to increase the duration of heatwaves. In cooler seas, the extra heat also can drive up their intensity, as seen in the Mediterranean Sea and the North Sea.

Dr Xiangbo Feng at the University of Reading, who was part of the study team, said: “As global temperatures continue to rise, marine heatwaves will become even more common and severe. Human activities are fundamentally changing our oceans. Urgent climate action is needed to protect marine environments.”

The climate crisis has tripled the length of ocean heatwaves, a study has found, supercharging deadly storms and destroying critical ecosystems such as kelp forests and coral reefs.

Half of the marine heatwaves since 2000 would not have happened without global heating, which is caused by burning fossil fuels. The heatwaves have not only become more frequent but also more intense: 1C warmer on average, but much hotter in some places, the scientists said.

The research is the first comprehensive assessment of the impact of the climate crisis on heatwaves in the world’s oceans, and it reveals profound changes. Hotter oceans also soak up fewer of the carbon dioxide emissions that are driving temperatures up.

“Here in the Mediterranean, we have some marine heatwaves that are 5C hotter,” said Dr Marta Marcos at the Mediterranean Institute for Advanced Studies in Mallorca, Spain, who led the study. “It’s horrible when you go swimming. It looks like soup.”

As well as devastating underwater ecosystems such as sea grass meadows, Marcos said: “Warmer oceans provide more energy to the strong storms that affect people at the coast and inland.”

One disastrous example was the intense rainfall that caused catastrophic flooding in Libya in 2023, which killed 11,000 people. It was made up to 50 times more likely by global heating, which had raised temperatures in the Mediterranean by as much as 5.5C. That resulted in more water vapour and therefore more rain.

“The only solution is cutting the burning of fossil fuels. This is a very clear relationship,” said Marcos. “More than 90% of the extra heat [trapped by greenhouse gas emissions] is stored in the ocean. If you stop warming the atmosphere, you will stop warming the ocean.”

Recent major marine heatwaves include an exceptionally long event in the Pacific in 2014-15, which caused mass mortality among marine life. Intense heat hit the Tasman Sea in 2015-16 and record sea temperatures around the UK and in the Mediterranean Sea in 2023. Scientists had warned in 2019 that ocean heatwaves were increasing sharply, killing swathes of sea-life like “wildfires that take out huge areas of forest”.

Dr Zoe Jacobs at the UK’s National Oceanography Centre, who was not part of the study team, said: “Ocean heatwaves pose significant risks to society, with some individual events causing millions of dollars of losses due to impacts on the fishing, aquaculture and tourism industries. They have also been found to exacerbate heatwaves on land and have amplified extreme weather like hurricanes and storms.”

The study, published in the Proceedings of the National Academy of Sciences, built a model of sea surface temperatures since 1940 that removed the heating the climate crisis has caused. They then compared that with actual measurements from the oceans to show how global heating has pushed up temperatures. They focused on summer heatwaves, because they reach the highest temperatures and are therefore the most damaging.

The analysis revealed there were about 15 days of extreme heat a year at the ocean surface in the 1940s, but the figure had jumped to a global average of nearly 50 days a year. Some regions, including the Indian Ocean, the tropical Atlantic and the western Pacific have 80 heatwave days a year, ie one day in every five.

The seas in the tropics are already warm, so the extra heat tends to increase the duration of heatwaves. In cooler seas, the extra heat also can drive up their intensity, as seen in the Mediterranean Sea and the North Sea.

Dr Xiangbo Feng at the University of Reading, who was part of the study team, said: “As global temperatures continue to rise, marine heatwaves will become even more common and severe. Human activities are fundamentally changing our oceans. Urgent climate action is needed to protect marine environments.”

Pressure is mounting on the United Arab Emirates over its presence at a crucial conference in London aimed at stopping the war in Sudan after a leaked confidential UN report raised fresh questions over the UAE’s role in the devastating conflict.

The UAE has been accused of secretly supplying weapons to Sudanese paramilitaries via neighbouring Chad, a charge it has steadfastly denied.

However an internal report – marked highly confidential and seen by the Guardian – detected “multiple” flights from the UAE in which transport planes made apparently deliberate attempts to avoid detection as they flew into bases in Chad where arms smuggling across the border into Sudan has been monitored.

The allegations raise complications for the British foreign secretary, David Lammy, who controversially invited the UAE alongside 19 other states for Sudan peace talks at Lancaster House on 15 April.

The date marks the second anniversary of a civil war that has caused the world’s biggest humanitarian crisis, displacing more than 12 million people.

A senior diplomat, who is familiar with the leaked report but requested anonymity, said: “The UK needs to explain how it is responding to massacres of children and aid workers while hosting the UAE at its London conference.”

The 14-page report – completed last November and sent to the Sudan sanctions committee of the UN Security Council – was written by a panel of five UN experts who “documented a consistent pattern of Ilyushin Il-76TD cargo flights originating from the United Arab Emirates” into Chad, from where they identified at least three overland routes potentially used for transporting weapons into neighbouring Sudan.

They found that the cargo flights from airports in the UAE to Chad were so regular that, in effect, they had created a “new regional air bridge”.

They noted that flights demonstrated peculiarities, with planes often disappearing for “crucial segments” of their journey, a pattern that the experts said “raised questions of possible covert operations”.

However, the experts added that they could not identify what the planes were carrying or locate any evidence that the planes were transporting weapons.

The findings of numerous cargo flights from the UAE to Chad are not mentioned in the final report of the UN expert panel on Sudan, due to be published in a few days. No reference is made to the Emirates in the expert’s final 39-page report except in relation to peace talks.

Questions over the UAE’s alleged role in backing the paramilitary Rapid Support Forces (RSF) arrive after a weekend that saw its fighters kill more than 200 civilians in a wave of violence against vulnerable ethnic groups in displacement camps and around the city of El Fasher, the last major city still held by the Sudanese army in Darfur, the vast western region of Sudan.

“It will be shameful if the conference does not deliver concrete civilian protection in the context of ongoing genocide,” said the diplomat.

In January the US formally declared that the RSF had committed genocide in Sudan.

The UAE states that it is committed to bringing “lasting peace“ to Sudan.

In their November update, the UN experts, investigating the possible smuggling of weapons from Chad into Darfur in possible violation of an arms embargo, identified at least 24 Ilyushin Il-76TD cargo flights landed at Amdjarass airport in Chad last year.

The flights, they noted, coincided with an escalation of fighting in El Fasher, in particular a “surge in drone activity primarily by the RSF for combat and intelligence” whose arrival in Sudan, said the experts, marked “a new technological phase in the conduct of hostilities”.

Some of the flights identified in the report were linked to operators previously connected to “military logistics and illicit arms transfers”. Two of them, said the experts, had previously been flagged for violations of the arms embargo.

Experts also examined “regular departures” into Chad from two UAE airports – in Ras Al-Khaimah emirate and Al Ain in Abu Dhabi emirate – and found that the flights frequently disappeared from radars during crucial moments.

On one occasion, the report describes how a flight “left Ras Al-Khaimah, vanished mid-flight, and later surfaced in N’Djamena [capital of Chad] before returning to Abu Dhabi”.

Crucially, however, the UN experts said they could not prove that the planes were carrying weapons because the “flights lacked evidence regarding the specific content being transported”.

Four of the five UN experts said that although the flights “marked an important new trend”, what they managed to uncover “failed to meet evidentiary standards regarding evidence of arms transfers”.

For instance, although residents of the South Darfur city of Nyala reported “cargo plane activity and informants attributed it to RSF logistical operations, further triangulated evidence to confirm the nature of the cargo transported was absent”.

Therefore, the experts said, it was “premature to infer that these flights were part of an arms transfer network”. They also added that the fact that several of the flights and cargo operators were linked to military logistics and past arms violations “did not provide proof of current arms transfers”.

It added: “Additionally, patterns and anomalies in flight paths, such as mid-flight radar disappearances and unrecorded take-offs, raised concerns but did not offer verified evidence directly linking these flights to arms shipments.”

It said “closing these investigative gaps was crucial”.

The revelations come days after the international court of justice (ICJ) in The Hague heard a case brought by Sudan accusing the UAE of being “complicit in the genocide” during the war. The ICJ has heard claims that the RSF is responsible for serious human rights violations including mass killings, rape and forced displacement in West Darfur.

The UAE has said the case is a cynical publicity stunt and a “platform to launch false attacks against the UAE”.

A UAE source pointed out that the confidential UN expert report contained the disclaimer that four of the five panel members felt that “allegations of an airbridge from the UAE to Sudan via Chad failed to meet the evidentiary standards required to establish a clear link between the documented flights and the alleged transfer of arms”.

A UAE statement added that the imminent final report from the Sudan expert panel did not reference the Emirates in relation to any flights “because the allegations against us failed to meet the panel’s evidentiary threshold. The record speaks for itself.”

It added that they had been told by the UN security council’s Sudan sanctions committee that the final report “did not make any negative findings” against them.

“The latest UN panel of experts report makes clear that there is not substantiated evidence that the UAE has provided any support to RSF, or has any involvement in the conflict,” said the statement.

Southern Californians were rattled on Monday morning when a strong earthquake shook the areas around San Diego just after 10am local time.

Initial measurements from the United States Geological Survey rated the temblor as a magnitude 5.2, with an epicenter in Julian, a mountain town in San Diego county with roughly 2,000 residents known for its apple pie, located roughly 35 miles north-east of San Diego and 120 miles south of Los Angeles.

There was a low likelihood of damage or injuries from the quake, according to the USGS, which reported that “overall, the population in this region resides in structures that are resistant to earthquake shaking”. There are some vulnerabilities though, and earthquakes in this area have led to other dangers, including landslides and liquefaction.

The San Diego county police and sheriff’s departments said they had received no immediate reports of damage or injuries. A county firefighter who answered the phone at the Julian fire station also said there were no reports of damage and no calls for service.

California’s governor, Gavin Newsom, said on social media that he had been briefed about the earthquake and was working with local responders to determine whether there had been damage and if there was a need for more emergency response.

The earthquake was a test of the state’s “Shake Alert” system, which is designed to warn those who could be affected and give them essential seconds to prepare before shaking starts.

Operated by the USGS, the system sends out warnings through cellphone apps, the Android operating system and wireless emergency alert systems. Alerts rang out on phones across the region warning people to drop, cover and hold. In San Diego, roughly 40 miles away from the epicenter, the warnings gave people close to 14 seconds to respond before shaking began.

The quake swung light fixtures and rattled shelves in San Diego and was felt as far north as Los Angeles. Riley Ozuna, owner of the Julian Cafe & Bakery, said some cups fell on to the ground at her business. “But everything is OK,” she said.

“I thought the single-pane windows were going to crack because they were shaking pretty good, but they didn’t,” said Paul Nelson, the owner of a former goldmine that operated in the 1870s in Julian. He said some picture frames on the counter at the gift shop fell over at the Eagle Mining Co, but the tunnels that tourists can explore suffered no damage.

Schoolchildren were escorted outside buildings as a precaution when the ground started moving, said Capt Thomas Shoots of the California department of forestry and fire protection for San Diego county. He got a shake alert and then started feeling things rolling and banging.

“There was a lot of shaking and rattling around,” he said. “But thankfully everything seems to be back to normal.”

It was the second earthquake to hit the area in a matter of hours, with a 3.5 magnitude quake that registered around 4pm on Sunday.

Monday’s quake struck 8.3 miles (13.4km) deep near the Elsinore fault zone, one of the busiest seismic areas in California and part of the famous San Andreas fault system that usually sees at least one magnitude 4.0 quake every year, according to Lucy Jones, a veteran seismologist in southern California. Jones said that Sunday’s earthquake was a foreshock to Monday’s larger one.

Aftershocks also shook the area immediately following the larger quake, with a 3.0 and a 2.5 registered in Julian minutes after the first.

The Associated Press contributed to this story

Hungarian lawmakers have voted through a controversial constitutional amendment that campaigners described as a “significant escalation” in the government’s efforts to crack down on dissent and chip away at human rights.

Backed by the prime minister, Viktor Orbán, and his rightwing populist party, Fidesz, the amendment passed on Monday along party lines, with 140 votes for and 21 against.

It codifies the government’s recent ban on Pride events, paving the way for authorities to use facial recognition software to identify attenders and potentially fine them.

The amendment, which the government says prioritises the protection of children’s physical, mental and moral development, also enshrines the recognition of only two sexes, providing a constitutional basis for denying the gender identities of some in Hungary.

Amid Orbán’s repeated claims of foreign interference in the country’s politics, the amendment also allows the government to temporarily suspend Hungarian citizenship in the case of dual nationals deemed to pose a threat to the country’s security or sovereignty.

The Hungarian Helsinki Committee, a rights group, described the amendment as a means of “legislating fear” in the EU country. “These laws represent a significant escalation in the government’s efforts to suppress dissent, weaken human rights protection and consolidate its grip on power,” it said in a statement.

The opposition Momentum party highlighted similarities with restrictions in Russia. Much like Vladimir Putin, Orbán has sought to portray himself as a champion of traditional family values, ushering in policies that include blocking same-sex couples from adopting children and barring any mention of LGBTQ+ issues in school education programmes.

Before Monday’s vote, Momentum issued a call on social media for Hungarians to join it in a blockade of the country’s parliament, in the hope of keeping lawmakers from voting in the legislation. “Let’s collectively prevent them from leading us down the Putin road and depriving us of our freedom,” it said.

On Monday, opposition politicians and other protesters attempted to block the entrance to a parliament parking garage, with some using zip ties to bind themselves together, and were physically removed by police.

The constitutional amendment was approved almost a month after lawmakers fast-tracked a law that banned public events held by LGBTQ+ communities. Thousands of people have since taken to the streets, blocking bridges and major thoroughfares with chants of “democracy” and “assembly is a fundamental right” in weekly protests.

“This government isn’t just dismantling democracy brick by brick, it’s now going at it with a bulldozer,” Ákos Hadházy, an independent lawmaker who campaigns alongside Momentum, said at a recent rally, according to Bloomberg. “We are here because we need to act fast to get ahead and stop it.”

Orbán and his government have said their aim is to protect children from what they describe as “sexual propaganda”, but analysts have pointed to forthcoming elections to argue that the country’s LGBTQ+ minority is being scapegoated by a government intent on mobilising its conservative base.

Orbán, who has long faced criticism for weakening democratic institutions and gradually undermining the rule of law, is facing an unprecedented challenge from a former member of the Fidesz party’s elite, Péter Magyar, before next year’s elections.

As news of the Pride ban broke last month, 22 European embassies in Hungary, including those of the UK, France and Germany, issued a joint statement saying they were deeply concerned that the legislation would result in “restrictions on the right of peaceful assembly and the freedom of expression”.

The EU’s equality commissioner, Hadja Lahbib, also weighed in, writing on social media: “Everyone should be able to be who they are, live & love freely. The right to gather peacefully is a fundamental right to be championed across the European Union. We stand with the LGBTQI community – in Hungary & in all member states.”

The organisers of Budapest Pride, which regularly attracts tens of thousands of people, said they were determined to go ahead with this year’s march on 28 June. “This is not child protection, this is fascism,” they said last month.

The amendment, the 15th to Hungary’s constitution since it was unilaterally authored and approved by the ruling Fidesz-KDNP coalition in 2011, also seeks to reinforce Orbán over what he claims are foreign efforts to influence Hungary’s politics.

In a recent speech laced with conspiracy theories, Orbán pledged to “eliminate the entire shadow army” of foreign-funded “politicians, judges, journalists, pseudo-NGOs and political activists”.

Rights groups described the amendment as a step in this direction for Orbán, a self-described “illiberal” leader, because it allows for the suspension of Hungarian citizenship for up to 10 years for dual nationals deemed to pose a threat to public order or security. The suspensions would only apply to Hungarians who hold citizenship of another country that is not a member of the EU or European Economic Area.

The Hungarian Helsinki Committee, the Hungarian Civil Liberties Union, Amnesty International and the Háttér Society have urged the European Commission to launch a procedure against Hungary’s government, arguing that the recent changes breach EU law.

The groups highlighted the “gravity and urgency of the consequences of the adopted changes” in a recent statement, noting that they would “force LGBTQ+ people completely out of the public eye”. The nationwide ban is believed to be the first of its kind in the EU’s recent history.

The groups also said the amendment went further than violating the rights of LGBTQ+ people and those who supported them, describing it as a tool to further instil fear among those who voice dissent in the country. “The changes have overarching consequences that affect fundamental rights well beyond the issue of Pride,” they said.

Republican supporters of Ukraine are using the Kremlin’s deadly missile strikes as their latest evidence to convince Donald Trump that he must increase pressure on Vladimir Putin if he wants to reach a ceasefire deal.

Pro-Ukraine lawmakers and aides in the Republican party have carefully navigated Trump’s apparent affinity for Putin and avoided direct intervention in their efforts to shift his support toward Kyiv. But following the Russian strikes during Palm Sunday celebrations in the city of Sumy, advisers and allies have been highly vocal in condemning the attack using language meant to resonate with the US president’s conservative, religious base.

“Putin and peace apparently do not fit in the same sentence,” wrote Lindsey Graham, the Trump-allied senator who has sought to balance his support for Ukraine with his desire to remain on Trump’s good side. “Russia’s barbaric Palm Sunday attack on Christian worshippers in Ukraine seems to be Putin’s answer to efforts to achieve a ceasefire and peace,” he wrote.

“While Ukraine has accepted President Trump’s ceasefire proposal, Putin continues to show he is more interested in bloodshed than in peace,” said Michael McCaul, a representative for Texas. “Targeting innocent civilians as they gather to worship on Palm Sunday is beyond the pale.”

The strike came less than 48 hours after Steve Witkoff, the Trump envoy, met with Putin in St Petersburg. The Kremlin called the meeting “extremely useful and very effective”, although there was no indication that the two men achieved concrete results. Witkoff’s gesture of holding has hand over his heart when he saw Putin has been criticised in Washington as excessively fawning and naive.

Witkoff reportedly told Trump after a previous meeting with Putin adviser Kirill Dmitriev that the quickest way to end the war would be to recognise Russian control over the four Ukrainian regions it has sought to annex. Reuters reported that several Republican lawmakers were so concerned about Witkoff’s pro-Kremlin positions that they called the national security adviser, Mike Waltz, and the secretary of state, Marco Rubio, afterward to complain.

Trump said he had been told that the Russians had “made a mistake” in the strike on Sumy. The double-tap strike killed at least 34 and wounded more than 100.

The strikes have further invigorated a circle of advisers around Trump who have remained more wary of Putin but have largely been overshadowed by Ukraine skeptics such as Witkoff and the US vice-president, JD Vance.

Keith Kellogg, the Ukraine envoy who has largely been sidelined from the negotiations, said: “Today’s Palm Sunday attack by Russian forces on civilian targets in Sumy crosses any line of decency. There are scores of civilian dead and wounded. As a former military leader, I understand targeting and this is wrong. It is why President Trump is working hard to end this war.”

Richard Grenell, the Trump special envoy who has also led his culture war at the Kenendy Center, wrote: “Attacking on the holy day of Palm Sunday?! Dear God.”

The messaging is likely to resonate most among the religious right, a key constituency for Trump and for many of his supporters in the US Congress. A previous campaign to raise awareness over Russian persecution of Christian religious groups in east Ukraine was seen as instrumental in lifting Republican opposition to a supplemental funding bill that included about $61bn for Ukraine and replenishing US weapons stockpiles.

Some of those supporters are also pushing for tougher sanctions against Russia. “Unless there is a dramatic change soon, it is obvious to me that the only hope of ending this war is to continue to cripple Russia’s economy and punish those who prop up Putin,” said Graham.

The Ukrainian government has said that the attacks show that Russia is ignoring the US calls for a ceasefire. “It’s now the second month that Putin has been ignoring the US proposal for a full and unconditional ceasefire,” wrote Zelenskyy. “Unfortunately, there in Moscow they are convinced they can keep killing with impunity. Action is needed to change this situation.”

Trump had signaled even before the attack that he was growing exasperated with Russia’s intransigence – the first signs of frustration that many Ukrainian allies hope will develop further during his presidency.

But he stopped short of condemning the strike which he described as a “mistake”, and on Monday, he appeared unswayed by an invitation by Zelenskyy to come to Ukraine and see the results of the attacks for himself. “I HAD NOTHING TO DO WITH THIS WAR, BUT AM WORKING DILIGENTLY TO GET THE DEATH AND DESTRUCTION TO STOP,” he wrote in a post.

Campaigners with Canada’s Liberal party had some very American-esque politicking over the weekend, when Liberal operatives were found to have planted “stop the steal” buttons at a conservative conference to link the Conservative party to Donald Trump.

Two Liberal party staffers infiltrated last week’s Canada Strong and Free Network Conference (CSFN) in Ottawa at which they strategically placed provocative buttons designed to create the false impression that Conservative supporters of party leader Pierre Poilievre were embracing Trump-style rhetoric, highlighting internal party divisions.

The operation was exposed when a Canadian Broadcasting Corporation (CBC) politics reporter overheard staffers boasting about their actions at an Ottawa pub, where they were drinking with other Liberal war room colleagues on Friday night.

One button featured the phrase “stop the steal” – directly echoing Trump’s baseless claims about the 2020 election results being stolen from him. Another displayed the name of Conservative national campaign director, Jenni Byrne, crossed out, with “Kory Teneycke” written underneath – referring to a leading Conservative strategist who has been publicly bashing Poilievre.

The CSFN conference, Canada’s less idealistic version of the Conservative Political Action Conference (CPAC), serves as a key gathering for conservative-minded Canadians to discuss policy proposals and network.

The incident comes in the final stretch of a heated campaign only weeks away from elections, in which the Liberals who hold a polling lead have consistently sought to characterize Poilievre as Canada’s version of Trump.

Poilievre’s confrontational style with mainstream media, his “Canada First” campaign slogan, and his frequent attacks on the CBC specifically as “government-funded media” have fueled these comparisons, despite his insistence on fundamental differences between himself and the US president. Just this Sunday on Radio-Canada’s popular talkshow Tout le monde en parle, when asked if he was a “mini-Trump, medium Trump or large Trump”, Poilievre quipped about his lighter weight before emphasizing his “completely different story” as the child of middle-class teachers compared with the US president’s inherited wealth.

The Liberal party confirmed the incident on Sunday evening, saying some campaigners had “regrettably got carried away” with buttons “poking fun” at reported Conservative infighting. A party spokesperson, Kevin Lemkay, added that the Liberal leader, Mark Carney, had made it clear “this does not fit his commitment to serious and positive discourse”.

Over the years, Poilievre has proudly associated himself as a culture warrior for Canada’s right, saying he wants the country to move away from “woke” to “warrior” and appearing on rightwing media like the Canadian influencer Jordan Peterson’s show.

The Liberal party has been able to take advantage of linking Poilievre to Trump after near country-wide disappointment and disapproval that followed the US president’s targeting of Canada as the supposed “51st state” and choosing to include its previously friendly neighbor in mass tariffs. As a result, there has been a near-total plunge in Canadian tourism to the United States, and the Liberals hold a tight lead in the polls under new leader Carney.

“Despite their public claims, it’s clear that it’s the Liberals who are attempting to bring American-style politics to our country,” the Conservative party spokesperson, Sam Lilly, said in a statement to CBC.