NSW needs new environment minister: Labor

The interim NSW opposition leader has called on the premier to stand up to climate sceptics in her party and appoint an environment minister who "actually understands the portfolio".

Penny Sharpe on Thursday said Premier Gladys Berejiklian had to appoint an environment minister who cared about the issues.

"The new environment minister must be someone who can hold their own in cabinet against rapacious anti-environment sentiment and climate change sceptics, including Treasurer Dominic Perrottet," Ms Sharpe said in a statement.

Mr Perrottet in 2015 said spending taxpayer money on some climate change measures was a "gratuitous waste".

The Treasurer has stood by the comments although last week he said he had always believed in the science of climate change.

Gabrielle Upton is the current environment minister but it's widely expected she will be dumped from the portfolio this weekend when Ms Berejiklian reshapes her cabinet after Saturday's election win.