The UN’s climate chief has ­declared Australia will let the world “overheat” and fruit will be a “once-a-year treat” if Labor does not lift its clean-energy ambitions, as Anthony Albanese prepares to trumpet an ambitious emissions target to world leaders in his bid to host the next global green summit. Following heated debate over climate change and the net-zero target in the first parliamentary sitting fortnight of the new term, during which Coalition MPs and conservative think-tanks argued the energy transition would cost billions, UN climate change executive secretary Simon Stiell demanded Australia not “settle for what’s easy” when enshrining its 2035 target. The top climate diplomat – who will meet Climate Change and ­Energy Minister Chris Bowen in Canberra on Tuesday – also warned unambitious interim targets would lead to a nosedive in Australia’s “high living standards” and make the current grocery price crisis “look like a picnic”. “Mega-droughts (will make) fresh fruit and veg a once-a-year treat. In total, the country could face a $6.8 trillion GDP loss by 2050,” Mr Stiell warned at an event hosted by the Smart Energy Council in Sydney on Monday. “Australia has a strong economy and among the highest living standards in the world. If you want to keep them, doubling down on clean energy is an economic no-brainer. Bog standard is beneath you. The question is: how far are you willing to go? “The answer is due in September – when Australia’s next national climate plan is due.”