The 2020 emissions reduction target New Zealand has put on the table in Copenhagen, a cut of 10 to 20 per cent from 1990 levels, is highly conditional.
In particular, the Government wants changes to the rules relating to forestry and to ensure New Zealand's ability to meet its obligations by importing "carbon" - or units representing a reduction in emissions somewhere else in the world - is not restricted.
Some countries seek to limit the ability to use international carbon markets to meet national targets, seeing them as reducing the incentive to reduce emissions though domestic action.
The Government is arguing for changes to the rules on deforestation, which currently say that when a forest is felled, unless that very land is replanted, all the carbon stored in those trees is deemed to be emitted to the atmosphere then and there and has to be counted in the country's emissions.
New Zealand says timber would not be much of a building material if that were true and that it ought not to matter whether the same land is replanted, only that a new forest is established somewhere which will suck up the same amount of carbon dioxide as it grows.
These issues are not expected to be settled at Copenhagen.
Climate Change Negotiations Minister Tim Groser says that until they are, New Zealand's offer will remain conditional.
"But I am concerned about this. Although New Zealand [has] made this position absolutely clear time after time, you always need to be concerned in an international negotiation that [other parties] at the end of the day are just going to regard this as something they don't want to know about and roll over the top of it."
Groser also contradicts the idea that the Government needed to enact amendments to the emissions trading scheme, which will impose costs on energy users from the middle of next year and farmers from 2015, before the Copenhagen conference.
"In all the discussions and negotiations on climate change I have had over the past 12 months, no one has ever asked me, formally or informally, a single question about New Zealand domestic policy."