With New Zealand-Australia alignment heating up under the National government, emissions trading harmonisation is on the agenda this week.

The two countries committed to combat global warming together during the fifth Australia New Zealand Climate Change and Business Conference In Melbourne yesterday.

Conference convenor Gary Taylor said the governments were working to create emissions trading regimes that would be broadly compatible, although this would not happen for five to ten years.

He said the two countries were becoming more aligned in general terms and harmonisation of emissions trading, as with other areas, would provide a bigger market for New Zealand, with more liquidity and opportunity.

Both countries have agreed to settle their emissions trading regimes prior to the United Nations Climate Change Conference in Copenhagen in December.

New Zealand's emissions trading scheme (ETS) is under review, while Australia's carbon pollution reduction scheme has yet to come before the senate.

Mr Taylor said he did not envisage agricultural emissions to be an issue, despite differences in the two countries' approach.  While agricultural emissions in New Zealand were "here to stay", Australia planned to decide on their inclusion in 2013 with a view of introducing them in 2015, he said.

"It's not as big a deal in Australia, as agricultural emissions account for 16%, whereas they makeup 50% here."

Earlier this week, head of the NZ Climate Change Research Institute at Victoria University Professor Martin Manning told the NBR that the agricultural sector needed to be onboard.  "There are techniques for reducing emissions, maybe only by 10%, but that's still important.'

He said there was a tendancy for farmers to hide behind the need for more research.

Mr Taylor said the New Zealand government's committment to the ETS and to a global research initiative gave it some international credibility.

However Mr Manning said the country would come in for international criticism if it did not start reducing agricultural emissions soon, adding that policy makers needed to tackle the complexity of the issue.