Good morning, this is Richard Parkin bringing you the main stories and must-reads on Friday 20 September.

Top stories

More than 250 Australian academics have publicly backed school climate strikes around the country, telling schoolchildren civil disobedience is required to “defend life itself” in the face of political inaction. Tens of thousands are expected to march at more than 100 locations across Australia today, with professors and researchers writing that it is “unconscionable” that current and future generations will have to bear the “terrifying brunt of this unprecedented disaster”. “When a government wilfully abrogates its responsibility to protect its citizens from harm and secure the future for generations to come, it has failed in its most essential duty of stewardship,” the open letter states. Follow coverage of the strikes throughout the day on our live blog, from 8.15am AEST.

A third blackface incident involving Justin Trudeau has been revealed, just hours after the Canadian prime minister apologised “profoundly” for wearing what he described as “racist” makeup to a costume party in 2001. The latest images came in a short, undated video clip published by Global News in which Trudeau – his face, arms and legs painted black – waves at the camera and sticks out his tongue. The opposition Conservative party – now neck-and-neck with Trudeau’s Liberals with an election weeks away – confirmed it had sent the video to Global News.

The immigration services provider Serco has been awarded a tender worth nearly $10m by the Australian government to return non-citizens to their home countries, despite the UN already providing such a service. Costing $415,000 a month for the next two years, Serco’s assisted returns program has drawn criticism from refugee advocates, given historic allegations of mistreatment during the company’s management of offshore detention centres.

World

Facebook Twitter Pinterest A burrowing owl near Calipatria, California. A study has revealed the shocking extent of bird losses in North America. Photograph: David McNew/Getty Images

The US and Canada have lost more than one in four birds since 1970 – a total of 3bn – culminating in what scientists who published a new study are calling a “widespread ecological crisis”.

Britain’s supreme court has been urged to back parliament’s recall next week, as a three-day emergency hearing into the legality of Boris Johnson’s proroguing of parliament concluded. The judgment will be handed down early next week.

Benjamin Netanyahu’s opponent Benny Gantz has rejected a power-sharing agreement in Israel, declaring that he should lead the next government.

Lawyers in the Netherlands have been given emergency protection after the murder of a top defence lawyer, amid media claims the country is descending into a narco-state.

The US secretary of state, Mike Pompeo, has cooled rhetoric against Iran, saying Washington is seeking a “peaceful resolution” of tensions with Saudi Arabia.

Opinion and analysis

Facebook Twitter Pinterest An installation view of Kaws: Companionship in the Age of Loneliness at NGV International, in Melbourne. Photograph: Tom Ross

After a painting that was essentially “a riff on a riff” sold for $14.8m, the art world was quick to round on its creator as “conceptually bankrupt”. But is there more to the artist known as Kaws than just a pop culture craze, asks Steph Harmon. “The figures are often talked about as cartoon or fun or whatever … but I think he’s responding very clearly to the rise of loneliness in our society,” says the curator Simon Maidment, as the National Gallery of Victoria launches a 25-year retrospective, including more than 100 works by the artist.

Brigid Delaney is travelling through Mongolia. She sits with nomads, eats their food, drinks cheap vodka and swims in lakes. Everything is going well, until ... “I’m lying … on a camp bed as hard as a door frame, when I get a sharp, stabbing pain in my abdomen. It’s like my digestive tract is studded in razor blades (similar to those rumours about razor blades on the waterslides at fun parks in the 1980s) and I’m trying to digest Mongolia’s biggest chunk of mutton. My stomach is making gurgling noises like ... like … something is trying to escape.”

Sport

Arsenal have demolished Eintracht Frankfurt in the Europa League, bouncing back from a disappointing performance in the Premier League against Watford, with their young stars spearheading a 3-0 win in Germany.

The Rugby World Cup has always been a tournament that demands consistency above all else. Yet the evenness of this year’s competition throws up the real possibility of a team losing a pool game and still managing to win, writes Bret Harris.

Thinking time: Pop music’s constant need for ‘new stuff’

Facebook Twitter Pinterest Pop albums are being released at an explosive pace

The studio album was once the pop industry’s most valued commodity, with the US music industry earning 92.3% of its revenue in 2000 from the sale of CD albums. While albums were released in the 1950s and 60s at the same breakneck pace as singles, driven in part by the immense commercial success of bands like the Beatles, by the 70s the rise of the LP changed “how we perceive and remember what was once the most evanescent of the arts”, according to the famed critic Robert Christgau.

With stars like Ariana Grande releasing new albums just six months after their last, and even indie acts such as Foals and Big Thief producing new music at a prolific rate, quick is back. But what’s behind the explosive pace of production? Aimee Cliff takes a closer look.

Media roundup

Australian federal police have heard eyewitness testimony implicating special forces soldiers in murder, the Sydney Morning Herald reports, with detectives travelling to Afghanistan to investigate allegations of war crimes. The peak body representing sports players globally has called for drastic overhaul of anti-doping regulations, writes the West Australian, claiming they have a “devastating impact on players’ lives”. And the Courier-Mail says Indonesia’s new laws criminalising consensual sex between unmarried adults could put 1.2 million Australians at risk of jail terms.

Coming up

Students and their supporters around Australia will take part in the global climate strike.

Scott Morrison arrives in the US for his official visit, which includes a state dinner at the White House hosted by Donald Trump.

Sign up

If you would like to receive the Guardian Australia morning mail to your email inbox every weekday, sign up here.