THE UN’s former climate change chief has warned Australia not to be ”too radical” in designing its carbon tax, but has urged the federal government to proceed with its policy.

Yvo de Boer, KPMG’s special global adviser on climate change, also questioned Opposition Leader Tony Abbott’s vow to repeal the tax if he won the next election, saying businesses across the world were demanding a bipartisan approach to climate policy.

”I think to be able to reverse something, you first have to know what it is. I don’t know what [Mr Abbott] would be reversing,” he said. ”What I hear from companies around the world is huge frustration that whenever an election happens somewhere in the world, policy is altered or reversed.

Yvo de Boer: clear direction needed.Yvo de Boer: clear direction needed.

”My sense is that Australian industry recognises that this is a key issue and that they need to act. I get the sense that the willingness to act is out there, providing that concerns about international competitiveness can be addressed.”

The calls for a clear direction on climate change were echoed by Coca-Cola Amatil chief executive Terry Davis, who said that while Australia should not lead the push to cut emissions, the country needed certainty.

”What does business want from government? They want consistent and consistently communicated policies and plenty of time to debate the issues so you don’t get these surprises when you wake up in the morning and all of a sudden there is a whole new tax,” he said.

Mr Davis said he believed it would be difficult for a coalition government to repeal the carbon tax.

”Once these taxes get in place and ever if there is a change in government, often it’s very difficult to actually repeal them, because the processes are put in place. But we will just have to wait and see.”

Mr de Boer said the European Union’s emissions trading scheme was ”not terribly” effective in reducing emissions when it started because of the number of free permits given to industry and the impact of the global financial crisis.

He said the two lessons for Australia were, firstly, ”don’t be too radical in the first step that you take” and, secondly, to include as many sectors of the economy as possible.

The government’s climate change adviser, Ross Garnaut, yesterday supported that position, saying the inclusion of agriculture under the tax would provide ”large advantages for the Australian farm sector”.