Friday’s top story: US to stage largest ever climate walkout in more than 1,000 locations. Plus, what to do about the mosquito, humankind’s deadliest predator

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Good morning, I’m Tim Walker with today’s essential stories.

Greta Thunberg and school students lead worldwide protest

Students and adults across America are joining a worldwide day of protest over the climate crisis on Friday, with strikes planned at more than 1,000 schools and workplaces in the US, the country’s largest ever mass climate demonstration. The global movement’s young figurehead, Greta Thunberg, will speak at a march in New York. The Guardian’s view: her message is simple and unignorable. In case you’re still not convinced, here is the climate crisis explained in 10 charts – and here’s how you can get involved.

Global health. The climate crisis is the biggest threat to global health over the next quarter-century, and governments are failing to prepare, according to a survey of the top medics who make up the membership of Britain’s Royal Society of Tropical Medicine and Hygiene.

Waterfront woes. New York City is taking action to protect the Lower Manhattan waterfront from the looming impact of climate change. But low-income residents who live by the water in other boroughs will have to fend for themselves, as Emily Nonko reports.

US and Canada have lost one in four birds since 1970

Facebook Twitter Pinterest A chestnut-sided warbler perched on a branch during spring migration. Photograph: Vince F/Alamy

The US and Canada have lost more than one in four of their birds – 3 billion animals in total – since 1970, a “widespread ecological crisis” outlined by scientists from both countries in a new study. The researchers observed a 29% decline in bird populations across diverse groups and habitats, from songbirds to long-distance migratory birds and backyard birds such as sparrows. Grassland birds suffered a staggering 53% reduction in population, while spring migration has fallen by 14% in the last decade alone.

Agriculture and urbanisation. The study, published in the journal Science, did not identify a specific reason for the decline, but bird populations and their habitats are thought to have been harmed by agriculture, urbanisation, climate change and cats.

Whistleblower rumours focus on Ukraine amid Giuliani claims

Facebook Twitter Pinterest Trump reportedly made a troubling promise to a foreign leader in a phone call. Photograph: Jonathan Ernst/Reuters

A whistleblower complaint submitted by a US intelligence official, who was unusually troubled by a promise Donald Trump had made to a foreign leader in a phone call, was connected to Ukraine, according to reports in the Washington Post and New York Times. The foreign leader in question has not been identified, but the complaint was reportedly filed weeks before Trump spoke to the new Ukrainian president, Volodymyr Zelenskiy.

Digging for dirt. Speaking to CNN on Thursday, the president’s lawyer, Rudy Giuliani, admitted asking Ukraine to investigate the former vice-president and 2020 presidential hopeful, Joe Biden, whose son once had a role in a Ukrainian gas company.

Iran rhetoric. The US secretary of state, Mike Pompeo, has dialled down the administration’s aggressive rhetoric in the wake of the recent attack on a Saudi oil facility, saying Washington wants a “peaceful resolution” with Iran, whom it blames for the attack.

Trudeau ‘can’t recall’ how many times he wore blackface

Play Video 2:07 Justin Trudeau says he does not remember how many times he wore blackface – video

Justin Trudeau has admitted he is “wary of being definitive” about the number of times he donned blackface as a young man, as the Canadian prime minister fights for his political life following the emergence of three separate, historical images of him wearing the racist makeup. The two photographs and a video all came out within 24 hours on Wednesday and Thursday, generating merciless criticism from rival party leaders less than five weeks before Canadians go to the polls on 21 October.

Political future. The blackface images have shattered Trudeau’s carefully curated image as a progressive leader, but the controversy may not shift the election needle as much as Canada’s Conservatives hope, as Leyland Cecco reports from Toronto.

Cheat sheet

Two people have died and at least 1,000 needed rescuing after the remnants of Tropical Storm Imelda brought an estimated 40in of rain to parts of Texas in less than 72 hours, making it the seventh-wettest tropical cyclone in US history.

The Los Angeles political activist and Democratic donor Ed Buck had at least 10 victims and preyed on gay, black homeless men, forcibly injecting them with fatal doses of drugs, according to court records released after his arrest this week.

A study suggests the mystery illness known as Havana syndrome , which afflicted US and Canadian diplomats in Cuba between 2016 and 2018, may have been caused by mosquito fumigation – and not, as the Trump administration claimed, by “sonic attacks”.

Grassroots progressive organisers in partnership with the Guardian will on Saturday host their first “people’s forum” in Iowa, featuring Bernie Sanders, Elizabeth Warren and several other Democratic 2020 candidates – though not the frontrunner, Joe Biden.

Must-reads

Facebook Twitter Pinterest Lilly Singh: ‘This is the new standard – take notes, Hollywood!’ Photograph: NBC/NBCU Photo Bank via Getty Images

Lilly Singh: from YouTube star to historic late-night host

A Little Late With Lilly Singh launched on NBC this week, making Singh the first queer woman of colour to host a network late-night show, the first YouTuber to land a network hosting gig – and, at 30, the youngest host in late night. Adrian Horton reports.

Man v mosquito: should we wipe out our biggest killer?

With an almost unmatched capacity to adapt, mosquitoes have spread to virtually every corner of the globe, carrying the diseases that make them humankind’s deadliest predator by far. We might soon be able to eradicate all 110 trillion of them. Timothy Winegard asks whether we should.

How my father gained – and then lost – unlimited free air travel

In 1987, Caroline Rothstein’s father became one of only a few dozen people to purchase an unlimited, lifetime AAirpass, letting him fly first-class anywhere in the world on American Airlines for the rest of his life. In 2008, the airline took it away – and, in the process, took something integral to who he was.

Can I survive with a phone that only texts and calls?

Dominic Rushe spends more than four hours a day on his iPhone, gaming, social networking and reading. So how would he manage when he replaced it with the Light Phone, a new – albeit old-fashioned – device that does nothing but call and text?

Opinion

The US and Britain have long styled themselves as the custodians of global democracy, says Pankaj Mishra, while failing utterly to spot the rot of their own political spheres.

While democracy was being hollowed out in the west, mainstream politicians and columnists concealed its growing void by thumping their chests against its supposed foreign enemies – or cheerleading its supposed foreign friends.

Sport

The role of quarterback was once considered off-limits to black footballers. But, as the NFL enters its second century, the league’s most accomplished young signal-callers are predominantly players of colour, as Patrick Hruby reports.

Frank Lampard is still hunting his first home win as Chelsea manager. Getting off the mark against Liverpool on Sunday could be a tall order. That’s one of 10 things to look out for in the Premier League this weekend.

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