Brisbane: The Civil Society, known as the C20 for the duration of the G20 summit, has highlighted climate change and the "scourge" of youth unemployment as two of the biggest issues.
The C20 is a platform for dialogue between the political leaders of the G20 countries and representatives of civil society organiations.
"Civil Society said how can you even discuss energy efficiency without discussing climate change," C20 Australia's chairman Tim Costello said.
"The two are fundamentally linked and the game changer of the last couple of days with the deal between China and the US we believe raises inevitably the question of fairness of future generations," the Brisbane Times quoted Costello as saying.
Sally Sinclair, the coordinator of the "dialogue around inclusive growth and employment", said tackling unemployment across the globe was "fundamental" to addressing inequality across the globe.
"The growth plans that the G20 nations deliver will ultimately be judged on fairness," she said.
"There are 600 million young people across the globe who are not in education, training or employment. It is neither desirable nor economically sustainable," she added.
The C20 called for "strong, decisive action and leadership on" from the G20 on both issues, as well as those of profit shifting and tax and infrastructure investment.
It wants a plan that will lift the income of the bottom 20 percent of households within G20 nations.
The C20 leads the engagement with the G20 on behalf of international civil society.