CHINA has played a major card in negotiations in the run-up to the global climate change summit in Copenhagen, which is still eight months away.

China has put its own spin on what a "cap and trade" system should address.

It wants to see a logical extension of the "polluter-pays" principle, where consumer countries take responsibility for the carbon emissions generated in the manufacture of goods, instead of the producer countries that export them.

This came last week from China's top climate-change negotiator, Li Gao, who said 15-25 per cent of China's emissions now came from production for exports.

His numbers may be a little crude and short of the mark - a recent study by some Norwegian climate analysts found a third of all Chinese emissions are linked to exports.

US President Barack Obama has indicated his readiness to enter into an international agreement on emission reduction - unlike predecessor George Bush, who pulled out of the Kyoto agreement because it did not set binding targets for high-polluting developing nations such as China.

China's line that it won't take full toll of the emissions may appear to be a potential deal-breaker, but could equally provide the setting for a major compromise.

A deal between China and the US is seen as critical to the prospects of any agreement being reached - and for Australia's proposed emissions trading system to not place this country at a serious disadvantage.

The positions going into the summit might now seem far apart, but there surely is scope for compromise.

There is a case for importers and exporters sharing responsibility, because while the West has effectively outsourced emissions to countries where labour costs are lower and environmental restrictions less onerous, China has gained jobs and enormous wealth in the process.

But imagine the complexity of that system - as a consumer you could choose to avoid buying goods based on emissions information conveyed in label data.

Those who would argue against the "market" approach to emissions reduction suggest the flaw in the "cap and trade" system is that it charges money based upon the creation of the offending gases, yet there is no actual requirement for emitters to reduce or eliminate them.

Therefore, the responsibility to reduce such emissions can be avoided by any company that is willing to trade itself out of an obligation through elaborate offsets.

Along with that, China and India are no doubt attempting to deny any responsibility by trying to push the direct costs of a reduction system on to consumers.

Proponents of straightforward taxation of emissions also point out that there isn't a successful cap-and-trade scheme in operation that has actually resulted in a reduction in emissions.

Instead, it is claimed that such schemes have rewarded big polluters and created a new line of derivative instruments for brokers and financiers.

Let's not avoid a rigorous approach to dealing with the effect of industry and consumption on climate, but surely in addressing the issue we need to take time to ensure it is effective and fair.