THE state government is developing a new plan to combat climate change and it says it can make deep cuts to greenhouse gas emissions even if a proposal to build two new coal-fired power plants goes ahead.

The state's old greenhouse gas targets have been thrown out and replaced by a far more ambitious agenda to cut emissions by at least 5 per cent by 2020, instead of just stabilising them by 2025.

This means the average carbon footprint of every person in NSW will have to be reduced by a hefty 27 per cent in the next 10 years, according to federal government estimates. The NSW Department of Climate Change, Environment and Water says the plan is realistic even if there is no national emissions trading scheme by 2013.

The 5 per cent cut is still much less than scientists say is needed as part of the international effort to slow global warming, but it does bring NSW into line with the minimum national target.

The Premier, Kristina Keneally, has asked the Department of Environment, Climate Change and Water to report back to cabinet with the new plan by the end of the year.