Climate change protestors.

Rain won't halt their parade: Activists in Sydney braved thunderstorms on Sunday to demand action over climate change. Photo: Dean Sewell

Environment bureaucrats are deeply worried about their ability to develop a "working relationship" with their minister, so concerned they have refused a freedom of information request on the ground it could "complicate" the relationship.

The revelation came as organisers claimed 60,000 people came from around the country to rally for action on climate change, including some 10,000 in Sydney who braved torrential rain and chilly temperatures.

Asked by Fairfax Media for a copy of the incoming brief prepared for Environment Minister Greg Hunt, an official from the Department of Environment has replied that releasing it would have "a substantial adverse effect on the department's working relationship with the incoming minister".

"The public release of confidential advice prepared for the incoming government on a highly sensitive and public policy area such as climate change could complicate the relationship between the department and the incoming Coalition minister," assistant secretary David Williams wrote.

The briefing to which it has refused access contains "opinions, advice and recommendations on a full range of issues related to the Coalition's climate change policy".

The department says releasing it would "compromise the new minister's ability to quickly develop an understanding of the department's operations and sensitivities in climate change".

After receiving the briefing, the Coalition abolished the climate change department and merged it with the Department of Environment. Mr Hunt instructed the new department to prepare legislation to repeal the Clean Energy Act of 2011.

The act not only sets up the carbon tax and emissions trading scheme but also specifies a long-term emissions reduction target of 80 per cent below 2000 levels by 2050. If the bill becomes law, Australia will be committed to only one target - a reduction to 5 per cent below 2000 levels by 2020.

The Climate Change Authority (also slated for abolition in a separate bill) is preparing to recommend that the government boost its 2020 target to a cut of 15 or 25 per cent. It is also preparing to recommend an interim target of 50 per cent below 2000 levels by 2030.

The refusal to release the brief came as 130 protests around the country were held. They were organised by a coalition of activists, including GetUp! Members of the crowd carried placards with slogans such as, ''There's no Planet B'', ''My world in your hands'', ''One Climate, Our Future'' and ''Aim Higher on Climate''.

Huddling under a tree during a downpour, Keelah Lam, from Manly, said: ''It should be called climate chaos rather than global warming, because there is freaky weather all over the globe, and not just here.''

The Australian Greens gathered in Brisbane to start planning ways to improve their performance at the 2016 election. Leader Christine Milne said the Greens would ''not blink'' in the fight for strong action on climate change.

The Coalition's carbon tax repeal bills are unlikely to get through the Senate until the Greens and present independents lose the balance of power after June next year.

with Gemma Khaicy and Julie Power

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