Former prime minister Paul Keating says the landmark climate change deal struck between China and the US exposes the "nonsense" of the Abbott government's policies and its refusal to place the issue on the agenda of G20.

But Treasurer Joe Hockey says he's "not sure" if Beijing and Washington's move will ensure climate change will be front and centre of this weekend's G20 discussions in Queensland but urged leaders not to be distracted from what he said were the twin priorities of jobs and growth.

Climate change must be on the G20 agenda: Paul Keating Credit:Peter Braig

China and the United States stunned observers by announcing a secretly negotiated agreement that commits the US to cutting its carbon emissions by 28 per cent by 2025. Beijing has for the first time said its carbon emissions will peak by 2030.

Mr Keating has revealed he was aware of China and the US's private talks for seven months. He told the ABC's Lateline that the deal exposed, once and for all, the Coalition's foolishness in repealing the former Labor government's carbon tax.