Environment Minister Edwin Poots has been criticised for saying neither he nor his department officials believe there is a climate crisis.
Speaking to BBC's Talkback, the minister said that while he was committed to action he did not believe there was a current emergency.
"That is something that my department don't accept, so leaving myself to one side, the officials in my department don't believe that is appropriate language.
"The advice I have received from my officials is that language is not helpful, and there is a course of work we need to engage in and actions we need to take and we as a department will not be found wanting.
"People recognise that there is climate change that exists and we need to deal with that, and we deal with it in a rational way and we deal with sensibly and to get results. It's not about creating hysteria."
When asked about a Climate Change Act, Mr Poots said his staff were working on projects that were on the Green Growth initiative and other "far reaching actions " adding that they did not have time to "switch off the focus on things which are actually actionable to work on legislation which is more aspirational".
Green Party Leader Clare Bailey said that the "scientific evidence shows that climate breakdown is a reality" adding that she would "be alarmed if official policy was dictated by anything other than the science".
"The actions of our environment minister must be guided by the evidence showing the effects of greenhouse gas emissions, pollution and temperature rises," she said.
"That's why we need a Climate Change Act for Northern Ireland. It's not the time for denial or pushing climate breakdown down the priority list. We must make the just transition towards a low carbon economy, leaving no one behind."
Sinn Féin environment spokesman Philip McGuigan said Mr Poots "immediately needs to make his position clear".
"Given the scale and immediacy of the climate emergency we are facing, these remarks are little short of climate change denial," he said.
"Indeed, it explains the minister's repeated refusal to introduce a Climate Change Act.
"Our economy, society and way of life is existentially threatened by climate breakdown. We appear to be left with a minister who does not accept this fact.
"Minister Poots must explain his comments. Do his officials not accept the climate emergency, or is it his own beliefs?"