Each hectare felled costs taxpayers $495, with the losses in 2013-14 alone reaching almost $12 million, the Greens said, citing Forestry Corporation figures.

By contrast, the state's small plantation estate generates a profit of $5387 per hectare - and $114.4 million over the past three years - underscoring the need for the corporation to shift its focus, Greens forestry spokesman David Shoebridge said.

"It's an environmental and economic basket case," Mr Shoebridge said. "These are two million hectares of precious public forests that are being managed for a declining, loss-making logging industry."

For its part, the Forestry Corporation said the figures are distorted because as a land manager, it incurs costs for the entire estate for fire-fighting, weed control and road maintenance regardless of the amount harvested.

"The cost of managing these two million hectares is almost wholly recouped by the revenue raised from timber harvesting and the shortfall of around $7-8 per hectare, or 50 cents per house block, is fully offset by revenue from harvesting softwood plantations," a spokeswoman said.

By contrast, the National Parks and Wildlife Service receives about $350 million in state funding a year for its seven million hectares, she said.

Logging halt

As part of the Greens 2015 state election platform, the party would end all logging and mining in state native forests by 2016.

Areas of high conservation value would be transferred immediately to the National Park estate, with priorities including the Gardens of Stone forest near Lithgow, the Tanja and Mumbulla state forests of the south coast, and the Pilliga in the state's north.

To assist timber workers and communities to exit the industry, the Greens back an $80 million, four-year transition package, using money saved from halting logging losses. A parallel $40 million package over the same period would boost tourism and other economic activities.

"If we stop the logging then there is more than enough forest to accommodate bush walkers, mountain and dirt bike riders, horse riders and sensitive eco-tourism," Mr Shoebridge said. "This can all be done while promoting the environmental outcomes in every forest."

Chris Burns, a spokesman for the Motorcycle Council of NSW, said bike riders would back the Greens' policy.

"At the moment we get shut out of many areas," Mr Burns said. "If the logging is unsustainable, ... it's costing everyone money."

Mr Burns said "a surprising number of people are trying to get access to state forests", with individual motorcycle events already generating millions of dollars in business for Victoria and other states.

Kate Smolski, head of the Nature Conservation Council, also welcomed the Greens' policy as "visionary".

"The beauty of this package is that it will save taxpayers money while making major strides in protecting our forests and the wildlife they support," Ms Smolski said.

"The Greens and the ALP are standing up for the koala and our iconic wildlife," she said. "We urge the Liberal Party to match the Greens policies, and for Mike Baird to make good on his claimed desire to make NSW number one for the environment."

The Forestry Corporation spokeswoman said the economic benefits of state forest logging extend beyond the timber workers themselves.

"NSW has the largest number of hardwood sawmills in Australia and thousands of people are employed in the hardwood timber processing industry that native state forests supply," she said.