Environment groups welcome the merger with the energy portfolio but some warn the former resource minister might not be the right man for the job.
Environment groups are optimistic merging the federal energy and environment portfolios could transition Australia away from dirty power to renewables.
But some are warning appointing a minister formerly in charge of the mining sector could be a disaster for the nation's environment.
Prime Minister Malcolm Turnbull revealed on Monday former resources minister Josh Frydenberg would take on an expanded energy and environment portfolio as part of a post-election reshuffle.
Mr Frydenberg picks up environment from Greg Hunt, who has overseen the portfolio for almost a decade and will now focus on boosting innovation, science and Australian industry.
The Climate Institute is one of several environment groups which had pushed for the portfolio merger.
Chief executive John Connor said the two areas were "critically interrelated" and their coupling would require Mr Frydenberg to face up to the impact of one on the other.
"What we've seen in the past has been a hodgepodge of policies that has actually impacted investment," he told AAP on Monday.
It's a move also welcomed by the clean energy sector, which believes the merge "makes a lot of sense".
Clean Energy Council chief executive Kane Thornton reckons energy must be front and centre of Australia's efforts to deliver on international climate change commitments.
"It's a smart move," he told AAP.
"Obviously there's plenty of challenges in the two portfolios but there's a lot of interaction between them."
The Australian Conservation Foundation is hopeful the move could signal a change in policy direction, but warns Mr Frydenberg must throw his energy into renewables.
"If this government fails to lead on climate change this country is in very big trouble," chief executive Kelly O'Shannassy told AAP.
"There's not a real choice on transitioning to clean energy, it's going to happen, it is happening."
But some are concerned handing the environment portfolio to someone who has recently been focused on the nation's resources, like coal, could "bury the nation's environmental hopes".
Former Greens leader Bob Brown accused Mr Frydenberg of "whingeing" about environmental campaigns against him in his seat of Kooyong.
"In an age when new coal mines are criminal, the syndicates will be glad Mr Frydenberg has been appointed chief judge on this issue so vital to climate change and the planet's biosphere," he said.
And some resource groups are pleased.
Queensland Resources hailed the appointment a win, while the Australian Mines and Metal Association praised Mr Frydenberg's understanding of the need for a "diverse energy mix".
The Australian Pipelines and Gas Association reckons his new role will provide continuity for the energy and gas sector.
But environment and clean energy groups don't seem concerned by Mr Frydenberg's former job, saying they look forward to working with the minister to develop policies.