Matt Kean, the first NSW minister to hold the Energy and Environment portfolio, has told staff the two areas are "critical to the future of our state and planet".

In his first communication with staff in his new ministry, Mr Kean said he was "determined to take decisive and responsible action on climate change and ensure we protect our unique natural environment", according to the missive.

Matt Kean, the new Energy and Environment Minister, has made an impassioned first communication to staff. Credit:Brendan Esposito

Mr Kean's comments are the latest sign the Berejiklian government is planning to step up climate action despite making modest promises during the election campaign.

Mr Kean also sought to reassure employees concerned about the dissolution of the Office of Environment and Heritage, a move that blindsided senior officials within the former department.