The Baird government's future projection for NSW implies the state will extract more than 10 billion tonnes of coal at the rate of almost 1 million tonnes a day by 2056, forecasts the Greens say are "delusional" in a carbon-constrained world.

The NSW Intergenerational report released this month estimated Australia's richest state would swell in population by 50 per cent to 11.2 million in 40 years, with an annual output of $1.3 trillion by then.

The report also based its financial estimates in part on mineral volumes continuing to grow by 1.2 per cent a year. Thermal coal used in power stations currently accounts for 87 per cent of those volumes.