Inflation in Australia jumped to 4% in the year to August, up from 3.5%, because of higher global oil prices and the unwinding of last year's energy rebates, according to Treasurer Jim Chalmers. Speaking after the Australian Bureau of Statistics released the figures, Chalmers said the Middle East oil crisis was "overwhelmingly" to blame and that Australia is not immune from it.

"These numbers confirm that the overwhelming reason why inflation went up in August in headline terms was higher global oil prices," he said. "In fact, all of the increase in annual headline inflation was from a combination of higher fuel costs and the unwinding of last year's energy rebates."

Chalmers added that amid "heightened global instability" he was encouraged to see "underlying inflation moderate in the month-to-month figures" - though underlying inflation, which strips out volatile prices, remained unchanged at 3.6%. Both headline and underlying inflation are still far above the Reserve Bank's 2.5% target. "Inflation is still too high in our economy," he said. "That's why it is so important that we are managing the budget in a responsible way."

When pressed on the cause, Chalmers insisted: "That's not an opinion. It's a fact," adding that no "objective observer could contest that after today's figures." The RBA, meanwhile, lifted the official cash rate to 4.6% just yesterday, because apparently 4% inflation wasn't enough of a hint.

Former RBA governor Philip Lowe, in a podcast released by the Institute of Public Affairs today, called for governments to cut spending and run larger budget surpluses to reduce pressure on inflation and interest rates. NSW Premier Chris Minns defended his state's record, saying: "We've had the lowest increase in spending growth of any jurisdiction in the country" over the last four years. He added that every government has a responsibility to take demand out of the economy, and that NSW had been "careful with public money." Minns also said he wasn't going to comment on other governments, because that would require acknowledging they exist.

In other news that definitely isn't about inflation, Antarctic winter sea ice peaked at its third-lowest level on record, falling 1m sq km short of the long-term average. Satellites have been watching since 1979, and this year the ice peaked on 14 September at 17.59m sq km - about twice the size of Spain, or roughly one Spain short of normal. The four lowest years on record have all occurred in the past four years, which scientists say is a "now problem," as opposed to a "later problem," or the "never problem" that some politicians prefer.

Back in Australian politics, the Greens have a new leadership team: David Shoebridge is the new leader, replacing Larissa Waters, with Steph Hodgins-May as deputy. Shoebridge defeated Sarah Hanson-Young and outgoing deputy leader Mehreen Faruqi. Faruqi expressed disappointment, saying: "Of course, I am disappointed the party room chose another direction, and know many others will feel the same way." She also called for a member vote, because "without a member vote, we cannot call ourselves a grassroots party."

Shoebridge promised "material change" and mocked gradual politics: "What do we want? Gradual change! When do we want it? In due course!" He said Labor, the Coalition, and One Nation all practiced "dead politics." Hodgins-May added that families are desperate for housing and childcare, and anxious about the climate crisis while Labor "waves through new coal and gas projects."

Chalmers wished outgoing leader Larissa Waters well, saying he hadn't met the new leaders before. "I'm told that [Shoebridge] was particularly focused on the Labor party in his introductory remarks," Chalmers said, before pivoting to warn about the risks posed by One Nation, the Liberal party, and the National party. Because nothing says "good faith engagement" like immediately listing your opponents as threats.

Finally, in the only genuinely uplifting news: Oaka, a two-year-old koolie, has taken over from Bear as the koala detection dog. She will sniff out koalas by their fur, often metres above ground, and will work alongside drones and human spotters to find koalas cut off from food and water after bushfires, floods, and cyclones. "It felt like we had struck gold twice," said Josey Sharrad of the International Fund for Animal Welfare. Oaka lives on the Sunshine Coast and is training for what is expected to be another devastating bushfire season. "Our koalas will need all the help they can get, whether it comes on two legs or four," Sharrad said. At least someone in this country has a job that makes sense.