In 1990, New Zealand's total greenhouse gas emissions were equivalent to 60.8 million tonnes (Mt) of CO2 equivalent (CO2-e). As of 2008, total greenhouse gas emissions had increased by 13.9 Mt (22.8 percent) to 74.7 Mt CO2-e, due largely to increasing energy emissions and deforestation. From 1990 to 2008, the average growth in total emissions was 1.3% per year. Between 2007 and 2008, total emissions fell by 0.1 Mt CO2-e.
Fluctuations in the trend are largely driven by emissions from public electricity generation. This category can show large year-to-year fluctuations because of the use of thermal stations to supplement the hydro-electric generation during dry years. Generation in a year with normal rainfall requires lower gas and coal use and a year with less rainfall requires higher gas and coal use. This is a different trend from the steady increase in emissions from coal and gas used in electricity generation found in many other countries. Other fluctuations are caused by changes in numbers of agricultural livestock due to droughts.
The Land use, Land-use Change and Forestry (LULUCF) sector represents a major sink for New Zealand, removing CO2. In 1990, New Zealand’s net greenhouse gas emissions were 29.7 Mt CO2-e after removals due to LULUCF. In 2008, net greenhouse gas emissions had increased by 18.8 Mt (63.2 per cent) to 48.5 Mt CO2-e. The increase in net emissions between 1990 and 2008 is larger than for total emissions because the net removals from LULUCF were greater in 1990 than in 2008.