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The Kyoto Protocol is an international agreement addressing the problem of climate change. It sets binding targets for developed countries that ratify it, aimed at limiting the amount of greenhouse gases they emit.
These targets are expressed as “assigned amounts”, measured in tonnes of carbon dioxide equivalent (tCO2-e). Assigned amounts are divided into assigned amount units (AAUs), a type of emission unit. Effectively, one emission unit is the right to emit one tCO2-e of greenhouse gas.
The Kyoto Protocol is a ‘cap-and-trade’ system. Each country is allocated a number of AAUs at the start of each commitment period. The number allocated matches their emissions target for that period. It’s also possible to earn other types of emissions units. For example, you can earn Removal Units (RMUs) by removing greenhouse gases from the atmosphere by planting trees.
At the end of each commitment period, each country needs to surrender emissions units to match its actual emissions for that period. If a country emits more than its limit, it will need to buy emission units to cover the excess. If a country emits less than its limit, it can sell its spare units.
New Zealand ratified the Kyoto protocol in 2002. For the first commitment period, from 2008-2012, we agreed to limit our emissions to 1990 levels. New Zealand’s initial assigned amount was 309,564,733 AAUs – five times (due to the five-year period) our emissions in 1990. If we emit more than this amount of tCO2-e, we’ll need to buy emission units from another country to make up the difference. If we emit less, we can either sell our spare units to another country, or keep them to use in future.
The NZ Emissions Trading Scheme (ETS) helps us meet our Kyoto target by:
Last updated: 15 October 2010