The Berejiklian government has been accused of diverting money from the state's Climate Change Fund to cover projects unrelated to its original mandate.

According to its annual report for 2017-18, the fund drew revenue from customer electricity providers and Sydney Water totalling almost $293 million but spent only $181 million. Since 2012-13, the fund has collected about $456 million more than it has spent.

Although primarily set up to mitigate against climate change through reducing carbon emissions - including cutting demand for water and energy - the government has lately shifted the outlays it has been making towards vaguely climate-related activities, the NSW Nature Conservation Council says.

The council cited this year's annual report showing $33.7 million was allocated during the last fiscal year to the Biodiversity Conservation Trust, $32.2 million for Protected Area Management - such as the National Parks and Wildlife Service - and the $27.6 million spent on "enhanced bushfire management and hazard reduction".