Green groups' concern over Owen Paterson record
Environmentalists have expressed fears that the reshuffle makes the government more likely to take decisions against the environment.
Former Northern Ireland secretary Owen Paterson has taken over the environment brief from Caroline Spelman.
Green groups are concerned about Mr Paterson's track record on shale gas and energy subsidies.
They also say the removal of Justine Greening could signal a U-turn on building a third runway at Heathrow.
The reshuffle is the first major restructuring since the Conservative-Lib Dem government came to power.
Ms Spelman, Conservative MP for Meriden, was made Environment Secretary when the Coalition took office in 2010.
Mr Paterson takes over a portfolio - the Department for the Environment, Food and Rural Affairs (Defra) - with a £2.2bn budget.
But it was reported in Conservative Home that he wants to end all energy subsidies and fast-track exploitation of shale gas.
This would shatter any ambition for the UK of keeping to targets for renewables or greenhouse gases.
As MP for North Shropshire, he has also campaigned against plans to expand output from Welsh wind farms because of the impact of pylons on the landscape.
And he is in favour of culling badgers. But Mr Paterson was widely praised by environmentalists for his conservation-minded policy paper on fishing whilst shadow fisheries minister from 2003-2005.
The North Shropshire MP is the brother-in-law of the leading climate change sceptic Matt Ridley.
He wants to expand airport capacity, which would also threaten climate targets.
This, together with the removal of Justine Greening and Theresa Villiers from the Department for Transport, has raised fears among environmentalists.
They believe Mr Cameron is clearing the way for a Conservative U-turn on its opposition to a third runway at Heathrow before the next election.
London Mayor Boris Johnson expressed anger over the move: "There can be only one reason to move her (Ms Greening) - and that is to expand Heathrow Airport," he explained.
Zac Goldsmith, the Conservative MP for Richmond Park and North Kingston, tweeted: "Greening's appointment 11 months ago indicated the PM's position on Heathrow was solid. Yielding so easily suggests panic, not principle."
But Jean Leston, senior transport policy adviser at WWF-UK, signalled a more relaxed tone: "Justine Greening has been an impressive minister, who has dared to stand up to the aviation lobby and question the need for Southeast airport expansion.
"Patrick McLoughlin's return to the Department for Transport is a welcome move and will surely continue Justine Greening's robust defence of Government and party policy on aviation."
Some groups hope Mr Paterson will be a strong champion of the countryside.
James Cooper, head of government affairs at the Woodland Trust, said: "Owen Paterson comes with strong rural credentials. He lists trees among his interests and, naturally, we welcome that.
"One of the most important issues in his in-tray is the Government response to the Independent Panel on Forestry's report on the future of England's forests. This provides an excellent early opportunity for him to be bold."