Good morning, this is Eleanor Ainge Roy bringing you the main stories and must-reads on Friday 23 March.

Top stories

The Trump administration has slapped trade sanctions on China, including restrictions on investment and tariffs on US$50bn (A$65bn) worth of products, sparking heightened fears of a trade war. The US announcement marked the end of a seven-month investigation into tactics China has used to challenge US supremacy in technology, including hacking commercial secrets and demanding US companies hand over trade secrets in exchange for access to the Chinese market.

Speaking at the White House, Donald Trump said the imposition of tariffs was part of an effort for fairness, noting that China imposed a 25% tariff on US cars, while the US only had a 2.5% duty on Chinese cars. “They charge us, we charge the same thing,” Trump said. The trade sanctions are likely to trigger retaliation. Even before the US president’s announcement, China’s foreign ministry said Beijing would “take all legal measures to protect our interest”.

Australia’s energy market operator says an additional 850MW of dispatchable generation capacity will be needed in New South Wales after the closure of the ageing Liddell power plant, unless AGL agrees to complete all three stages of its transition plan. In December AGL confirmed it would close Liddell in 2022 and replace the coal plant with a mix of renewables, gas power for peak periods and battery storage. The company’s decision to retire the coal plant defied extraordinary public pressure from the Turnbull government to keep it open for another five years. AGL rebuffed Canberra’s request and is proceeding with its own plan – a mixture of renewables, gas peaker plants, battery storage and other upgrades.

The Katter party has introduced legislation in Queensland to allow crocodile culling, but scientists warn that the only way to completely stop attacks would be to eradicate the species. The private member’s bill would allow culling by landowners, the harvesting of crocodile eggs, and hunting safaris led by Indigenous rangers. The number of crocodiles has increased dramatically since the 1974 decision by the Queensland government to give them protected status. Dr Adam Britton, a Northern Territory-based zoologist and crocodile expert, said even thinning the crocodile population to 1970s levels would not stop attacks. “You wouldn’t want to be the politician who said ‘it’s safe, go swimming guys’.”

The mummified remains of a tiny baby from a Chilean ghost town had malformations so bizarre they led to speculation about alien life. But now California scientists have extracted her DNA and confirmed the baby, known as Ata, carried mutations in at least seven genes known to cause major skeletal malformations or accelerate their development. The 15cm body was discovered 15 years ago, and appeared in a documentary as potential evidence for alien life. The bones of the baby, who appears to have died immediately after birth, had some features of a child aged six to eight. Instead of the usual 12 pairs of ribs, Ata had only 10 pairs, and her head was an elongated cone shape. Scientists hope the discovery of the mutations may help patients with skeletal problems.

The Australian government has accused green groups of deliberately misleading the public by raising concerns about the rollover of long-term logging agreements. The accusations from the federal assistant agriculture minister, Anne Ruston, were revealed after Guardian Australia reported the government itself had discussed concerns that the agreements were invalid as they are based on old scientific assessments. The minister wrote personally to the National Parks Association to say she was disappointed that the association was “engaged in a campaign to mislead the Australian people”.

Sport

Pat Cummins tore through the South African batting to reduce the home side to 266-8 at the close of play on the opening day of the third Test at Newlands. Dean Elgar scored an unbeaten century, but Cummins took four for 12 in eight overs to swing the day Australia’s way after the hosts had been cruising at 220-2.

Western Bulldogs captain Katie Brennan will not lead out her team in Saturday’s AFLW grand final after an appeal against a two-game ban was dismissed on Thursday evening, throwing a significant spanner in the works for the favourites in the final against Brisbane.





Thinking time

Four years since Malaysia Airlines flight MH370 left its planned flightpath on 8 March 2014 and headed towards the Indian Ocean, the plane’s disappearance is still one of aviation’s most perplexing mysteries. The Malaysian government has prepared a report on potential causes of the disappearance, but it will not be released until the latest search finishes in June. In the vacuum of information, theories – some more credible than others – have sprung up. From mass hypoxia to a rogue pilot, we examine the contending theories of what happened to MH370.

The Great Pacific garbage patch has far more debris than previously thought, and is now twice the size of France: up to 16 times larger than earlier estimated. Research published by Nature has found the mass of waste contains at least 79,000 tons of plastic, and is “increasing exponentially”. Does the clean-up team heading to the site this year have any real hope of tackling it?

Wanting to escape the office grind doesn’t make you a snowflake, writes Rhiannon Lucy Cosslett. The gig economy may be perilous, but there are good reasons millions of young people prefer being freelance. “To centre the office, to proclaim it so vital despite the vast array of human social experience, seems absurdly middle class,” writes Cosslett. “Is office culture limited and tyrannical? I have found it so at times. When you feel stuck, unappreciated and underpaid, then striking out on your own is an attractive option”

What’s he done now?

Reports that Joe Biden is preparing a run for the White House in 2020 have enraged Donald Trump. The president attacked the former vice-president on Twitter, saying Biden would “go down fast and hard, crying all the way” if he ever acted on a repeatedly expressed wish to “beat the hell” out of Trump over his comments about women.

Media roundup

The Age reports that “risky teachers” will be barred from working in Victorian schools in a bid to protect children, following a report by the paper of a teacher who told stories about incest to children and paid them for massages. The Herald Sun has “Labor in Crisis” on its front page, revealing that a state parliamentary committee will be set up to grill Labor MPs and the premier, Daniel Andrews, about the party’s 2014 election funding. And the ABC has fact-checked the move to make codeine pain-relief available only by prescription – will the move really save 100 lives a year?

Coming up

The former US president Barack Obama is in Sydney speaking at an event for The New Zealand-United States council at the Art Gallery of NSW.

The banking royal commission will round out its first fortnight of hearings in Melbourne with more evidence about poor credit card practices.

Supporting the Guardian

We’d like to acknowledge our generous supporters who enable us to keep reporting on the critical stories. If you value what we do and would like to help, please make a contribution or become a supporter today. Thank you.

Sign up

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