New Zealand confirmed yesterday it was joining the Copenhagen Accord on climate change and was submitting its existing conditional 2020 target for reducing carbon emissions.

The Copenhagen conference last December failed to achieve a binding global agreement on reducing greenhouse gas emissions and instead asked countries to commit themselves to individual targets.

Another conference will be held in Mexico at the end of this year.

Climate Change Minister Nick Smith said New Zealand had submitted its original conditional target range of 10 per cent to 20 per cent below 1990 levels by 2020.

The target is conditional on a global agreement being reached that sets the world on a path to limit global temperature rises to not more than two degrees Celsius, other countries making comparable efforts to New Zealand, and there being effective rules governing land use and forestry.

"For our 2020 target to be representative of our fair share, other developed countries will need to set higher targets. Alternatively, New Zealand will need to reduce its target to ensure comparability," said Mr Smith. Prime Minister John Key said expectations for the Mexico conference were not high and countries were still a long way from reaching agreement on a binding target.