Five Queensland cities have made it onto a conservation group's list of the 10 most sustainable cities in Australia. But the Australian Conservation Foundation warned residents not to rest on their laurels, saying the rankings simply compared cities with each other and none had done particularly well. The Sunshine Coast made it to second place on the foundation's sustainable cities index, with the region recording the best air quality of the 20 cities studied. Darwin finished at the top of the list, while Brisbane came third, bolstered by residents' frugal water use and a large number of Green-Star-certified building projects. Brisbane also had the lowest type-two diabetes rate, but fared poorly in the ecological footprint stakes because of the large amount of land required to feed, clothe and house each resident. The sustainable cities index ranked Australia's 20 largest cities in 15 categories related to environmental performance, quality of life and resilience to future challenges.