Representatives of civil society want climate change to be a focus of G20 talks later this year but the government says it is not the best forum.

Civil society groups want climate change to be a main topic at a G20 meeting later this year, but Foreign Minister Julie Bishop says the forum should have an economic focus.

“If left unchecked, climate change could cost trillions of dollars to our economy, and perhaps shave around two per cent off growth, which is one of the principal focuses of the G20,” WWF Australia CEO Dermot O’Gorman told reporters in Melbourne on Friday.

He said the November summit in Brisbane is the appropriate forum to address the crucial issue.

But Ms Bishop told civil society groups meeting in Melbourne that the G20 could not be “all things to all people”.

The best forum to address global warming was the UN framework convention on climate change rather than the G20, which had a more economic focus, she said.

However, the G20 should focus on eliminating subsidies such as fossil fuel subsidies, which would cut global greenhouse gas emissions by at least 10 per cent by 2050, she said.

Ms Bishop said a key focus of the Group of 20 industrialised nations should be getting more women into the global workforce.

She said the capacity of millions of women around the world was being seriously under-utilised in contributing to national and global economic growth.

More family-friendly workplaces, tax concessions for businesses to help women return to work, support for part-time employment, better parental leave, and changes in laws and attitudes to sexual harassment and domestic violence were needed.

“Investing in women is not just the right thing to do, it’s the smart thing to do,” she said.

Labor foreign affairs spokeswoman Tanya Plibersek told the conference it was critical for countries to act together on climate change and called for greater transparency and anti-corruption measures to cut poverty.

Chairman of the two-day C20 Melbourne summit, Tim Costello, said the most vulnerable should not get left behind.

A protester angry about job losses and university fees yelled and lunged at Ms Bishop’s car as she left the forum at Melbourne University.

The summit’s recommendations will be presented to Prime Minister Tony Abbott on Sunday.