Climate change: a U-turn on methane

I've been reading the Local Government and Environment Committee's report on the estimates for Vote Climate Change and Energy Efficiency [PDF], which includes a long transcript of the evidence given by Climate Change Minister David Parker. During this evidence, National MP Eric Roy asks

[W]hat is your response to those who would say that animal emissions are neutral, because they are consuming plant material that is taking in its carbon from the atmosphere anyway?

Roy's question is simply ignorant; "animal emissions" are methane, a greenhouse gas 21 times worse than the atmospheric carbon dioxide they are effectively eating, so there's nothing "neutral" about them. But Parker's answer is also revealing:

I think there are arguments to be made that, in future international negotiations, New Zealand should be trying to argue that different rules should apply to different sorts of emissions. It seems a logical negotiating position to take that if there are practical technologies to reduce carbon dioxide emissions, you ought to expect greater reductions of carbon dioxide emissions than you would in respect of methane emissions, if there are no technological fixes. That is a position that New Zealand is adopting in international negotiations.

(Emphasis added)

Why is this interesting? Because it is a complete U-turn on our previous position. New Zealand emits a lot of methane (our per-capita methane emissions are nine times the global average), and as Parker notes, we don't see many ways of reducing it short of killing cows and throwing them in a ditch (though strangely, the Europeans have managed to make a 25% cut without such measures). So back in the 90's, when Kyoto was being negotiated, we argued very strongly that all greenhouse gases should be aggregated together, and reduction targets set accordingly, rather than each country having a target for CO₂, a target for methane, a target for nitrous oxide etc. Parker is now suggesting a complete reversal of this position, and the setting of seperate targets for methane and CO₂. Does he really think the countries we are negotiating with won't notice - or that they'll accept such transparent special pleading from a country which has repeatedly backed away from taking serious steps to meet its obligations?