THE lives of some of NSW's cuddliest residents are hanging in the balance, the Australian Greens warn.Greens senator Lee Rhiannon said koalas were under "enormous threat" in NSW and key populations across the state in Gunnedah, Port Stephens and elsewhere were at risk of disappearing.
"Their habitat is being compromised because of logging and over-development," she said.
"In so many areas, we're losing those environmental corridors that are absolutely essential if they're able to breed and to flourish."
Senator Rhiannon was one of several Greens campaigners who descended on Circular Quay on Saturday, calling for new national laws to protect native forests from logging.
The weekend rally launched a week of national campaigns against the March 2013 shift of commonwealth environmental approval powers to the states.
"If the government proceeds with its plans, which could eventuate at the COAG meeting this month - well, all that fine talk about environmental corridors will be nothing more than rhetoric and that's just not good enough," Senator Rhiannon said.
NSW Young Greens co-convenor Sam Dixon said the party's Too Precious to Lose campaign would ask people across the country to nominate Australia's most precious natural assets.
"In NSW, all of our national parks definitely belong on the list," Senator Rhiannon said.
"A lot of our estuaries along the coast, particularly for me, are very precious and they need to be protected."
She said many of the tourists who stopped to pose with a campaigner dressed in a furry koala costume might not have a good grasp of local conservation law, but they had no trouble identifying one of Australia's big drawcards.
The koala campaigner appeared unfazed by the 37C afternoon sun.
"This is my natural fur, I feel fine," he joked.