CARBON pricing can deliver incremental reductions in rich countries' greenhouse emissions but will not drive the discovery of cheap sources of clean power that are the only hope of stopping dangerous climate change, a former senior adviser to Kevin Rudd says in a new essay.

Andrew Charlton, who was so close to the former prime minister that some colleagues called him "the muse", says the world needs to admit that efforts to reach a legally binding global climate change treaty have failed.

"Carbon pricing will not, by itself, lead to the ... innovation we will need" ... Andrew Charlton.

As environment and climate ministers once again head off to an annual United Nations meeting, this time in Durban, which again has no chance of clinching an international agreement, Dr Charlton says the world needs to shift to a "plan B", focusing on research to find cheap clean power that all countries will want to use.

He now sees carbon pricing, which helped cost his former boss the prime ministership, as a way to "deliver incremental reductions in rich countries' emissions over time".