Canberra, Oct 11 : Environmentalists have advised the Australian government that it must do more to arrest a decline in biodiversity. Environment groups recently joined forces to urge Environment Minister Sussan Ley to make a pledge on halting biodiversity loss during the UN Biodiversity Conference, reports Xinhua news agency. Australia has committed to a global target of conserving at least 30 per cent of land by 2030 but has not made a specific pledge. Brendan Wintle, director of the Threatened Species Recovery Hub, said that Australia was at risk of becoming a "global pariah" on the issue. He estimated that Australia needs to spend up to A$2 billion ($1.4 billion) a year to halt biodiversity loss. "We can afford it, but we're not doing it, and that's on our leadership and our society," Wintle was quoted by Nine Entertainment newspapers in a report on Sunday evening. Australia has cleared more than 7 million hectares of threatened species habitat since 2000, mostly for agricultural use. The government in March acknowledged the extinction of 13 native species including 12 mammals. It takes the number of mammal species known to have gone extinct in Australia to 34. Nat Pelle from the Australian Conservation Foundation said the country's rich biodiversity meant it had more at stake. "We should decide as a planet -- and Australia especially -- not to allow threatened species to become extinct," he said. In response, a spokesperson for Ley said the government was working on a biodiversity framework. /IANS