Climate change in New Zealand involves historical, current and future changes in the climate of New Zealand; and New Zealand's contribution and response to global climate change. Summers are becoming longer and hotter, and some glaciers have melted completely and others have shrunk. In 2021, the Ministry for the Environment estimated that New Zealand's gross emissions were 0.17% of the world's total gross greenhouse gas emissions. However, on a per capita basis, New Zealand is a significant emitter, the sixth highest within the Annex I countries, whereas on absolute gross emissions New Zealand is ranked as the 24th highest emitter.
More than half (53%) of New Zealand's gross greenhouse gas emissions are from agriculture, mainly methane from sheep and cow belches. Between 1990 and 2022, New Zealand's gross emissions (excluding removals from land use and forestry) increased by 14%. When the uptake of carbon dioxide by forests (sequestration) is taken into account, net emissions (including carbon removals from land use and forestry) increased by 33% since 1990.
Climate change is being responded to in a variety of ways by civil society and the New Zealand Government. This includes participation in international treaties and in social and political debates related to climate change. New Zealand has an emissions trading scheme, and in 2019 the government introduced the Climate Change Response (Zero Carbon) Amendment Bill which created a Climate Change Commission responsible for advising the government on policies and emissions budgets.
New Zealand made a number of pledges on climate change mitigation in 2019: to reduce net carbon emissions to zero by 2050, to plant 1 billion trees by 2028, and to bring pastoral agriculture (farmers) into an emissions price policy by 2025. Already in 2019, New Zealand banned new offshore oil and gas drilling and decided that climate change issues would be examined before every important decision. In early December 2020, Prime Minister Jacinda Ardern declared a climate change emergency and pledged that the New Zealand Government would be carbon neutral by 2025. Key goals and initiatives include requiring the public sector to buy only electric or hybrid vehicles, government buildings will have to meet new "green" building standards, and all 200 coal-fired boilers in public service buildings will be phased out. International assessments of New Zealand's climate change actions are either ranked as "low" on the Climate Change Performance Index or rated as "highly insufficient" by Climate Action Tracker.
Greenhouse gas emissions
New Zealand has a relatively unique emissions profile. In 2022, agriculture contributed 53% of total gross emissions; energy (including transport), 37%; industry, 6%; waste, 4%. Based on the latest available Inventory data for 2022, New Zealand's gross emissions per capita were above the average for developed countries. In other Kyoto Protocol Annex 1 countries, agriculture typically contributes about 12% of total emissions.
Between 1990 and 2022, New Zealand emissions of carbon dioxide (CO2) increased by 24%; methane (CH4) by 2%; and nitrous oxide (N2O) by 35%. The total of all combined fluorinated gases have increased by 87%.
The New Zealand Emissions Trading Scheme, which came into effect in 2010, was intended to provide a mechanism which encouraged different sectors of the economy to reduce their greenhouse gas emissions. It may have slowed the increase somewhat. Between 2007 and 2017 total national emissions decreased 0.9%, reflecting growth in renewable energy generation.Greenhouse gas emissions have barely budged in a decade, new data shows Stuff, 27 June 2019 However, between 2016 and 2017, New Zealand's gross emissions jumped 2.2%, bringing the total (or gross) increase in greenhouse gas emissions between 1990 and 2017 to 23.1%.Rising NZ emissions sparks call for transport crackdown, NZ Herald 11 April 2019
In 2018, on a per capita basis, New Zealand was the 21st biggest contributor to global emissions in the world and fifth highest in the OECD.
Carbon dioxide New Zealand has a long-term record of atmospheric carbon dioxide similar to the Keeling Curve. In 1970, Charles Keeling asked David Lowe, a physics graduate from Victoria University of Wellington to establish continuous atmospheric measurements at a New Zealand site. The south-facing Baring Head, on the eastern entrance to Wellington Harbour, was chosen as being representative of the atmosphere of the southern hemisphere. Despite the majority of CO2 emissions coming from the Northern Hemisphere, the atmospheric concentration in New Zealand is similar.New Zealand's changing climate and oceans: The impact of human activity and implications for the future, An assessment of the current state of scientific knowledge by the Office of the Chief Science Advisor, July 2013 The Baring Head records show that CO2 concentrations rose from 325 ppm in 1972 to 380 ppm in 2009, and passed 400 ppm in 2015Carbon dioxide, Baring Head, New Zealand, NIWA and reached a new maximum of 416 ppm in December 2023.
Modelled wind directions indicated that air flows were originating from 55 degrees south. The Baring Head data shows about the same overall rate of increase in CO2 as the measurements from the Mauna Loa Observatory, but with a smaller seasonal variation. The rate of increase in 2005 was 2.5 parts per million per year. The Baring Head record is the longest continuous record of atmospheric CO2 in the Southern Hemisphere and it featured in the IPCC Fourth Assessment Report: Climate Change 2007 in conjunction with the better-known Mauna Loa record.
According to estimates from the International Energy Association, New Zealand's per capita carbon dioxide emissions roughly doubled from 1970 to 2000 and then exceeded the per capita carbon dioxide emissions of either the United Kingdom or the European Union. Per capita carbon dioxide emissions are in the highest quartile of global emissions.
Methane
The National Institute of Water and Atmospheric Research (NIWA) has also recorded atmospheric concentrations of methane (from 1989) and nitrous oxide (from 1997) at Baring Head. More than 80% of methane emissions in New Zealand come from enteric fermentation in ruminant livestock – sheep, cattle, goats and deer – with sheep the greatest single source.Methane, NZ Agricultural Greenhouse Gas Research Centre
This emissions profile is significantly different to that of other countries as, internationally, the dominant sources of methane are rice paddies and wetlands. As a greenhouse gas, methane is 28 times more powerful than carbon dioxide.FutureFeed, CSIRO A dairy cow produces between 84 and 123 kg of methane per year from rumen fermentation. Since New Zealand has large stock numbers these emissions are significant. In 1997, New Zealand's per capita emissions of methane were almost six times the OECD average and ten times the global average.
In 1997 Minister for Climate Change Issues Simon Upton stated that New Zealand's methane emissions from ruminant livestock industries were the highest per capita in the world.
Nitrous oxide Nitrous oxide is emitted primarily from agriculture, but also comes from industrial processes and fossil fuel combustion. Over 100 years, it was 298 times more effective than CO2 at trapping heat. In New Zealand in 2018, 92.5% of N2O came from agricultural soils mainly due to urine and dung deposited by grazing animals. Overall, N2O emissions increased 54% from 1990 to 2018 and now make up 19% of all agricultural emissions.
Agriculture , the agriculture industry was responsible for half of all emissions in New Zealand, but contributed less than 7% of the national Gross Domestic Product (GDP). In the decade prior there were modest reductions in emissions from sheep, beef, deer and poultry farms, but these were offset by a rapid growth in dairy farming which was the biggest increase in emissions of any single industry. Emissions from dairy had risen 27% over the decade such that this industry was responsible for more emissions than the manufacturing, electricity and gas supply industries combined.
Food processing In 2019, dairy collective Fonterra was responsible for 20% of New Zealand's entire greenhouse gas emissions. This was largely due to Fonterra's use of coal-powered boilers to dry milk into milk powder. Clean energy expert, Michael Liebreich, described the use of coal for this process as "insane". Genesis Energy Limited chief executive, Marc England, said in 2019 that Fonterra was using more coal than Genesis uses at its Huntly power station and should use electricity, which was already 85% renewable, in its milk powder factories.
Electricity The majority of New Zealand's New Zealand's electricity is hydroelectric. In the 2019 calendar year, 82.4% of the country's electricity was generated from renewable or low-carbon resources: 58.2% from hydroelectricity, 17.4% from geothermal, 12.6% from natural gas, 5.1% from wind, 4.9% from coal, and 1.7% from other sources.
In 2019, the Huntly Power Station consumed about 300,000 tonnes of coal and was one of the biggest carbon dioxide generators in the country contributing over half of New Zealand's emissions of greenhouse gases from electricity generation. According to Chris Baker, chief executive of Straterra, "that scenario won't change for years to come." Only 10% of the power from the Huntly plant was used by Genesis Energy Limited itself. The remaining 90% sold to other electricity companies to ease their own supply issues. In February 2018 Genesis Energy said it may keep burning fossil fuels until 2030.Our Inconvenient Truth: NZ will keep burning coal, Newsroom, 15 February 2018
A major barrier in decommissioning Huntly is ensuring continued security of supply, especially to Auckland and Northland. In June 2019, transmission grid operator Transpower analysed the effects of closing the two remaining coal-fired units at Huntly on its grid. It concluded that without the coal-fired units and no major new generation or transmission upgrades, voltage collapse could occur during Auckland and Northland winter peak demand from 2023 onwards with the 400 MW combined-cycle gas turbine Huntly Unit 5 out of service, or from 2019 onwards with both Huntly Unit 5 and any one of the 220,000-volt transmission lines from Whakamaru out of service.
Ten biggest polluters , the ten companies which emit the most greenhouse gases in New Zealand were Fonterra, Z Energy, Air New Zealand, Methanex, Marsden Point Oil Refinery, BP, Exxon Mobil, Genesis Energy Limited, Contact Energy, and Fletcher Building. These companies emit around 54.5 million tonnes of CO2 each year – more than two thirds of New Zealand's total emissions.
Favourable treatment for high polluters The seven biggest industrial emitters in New Zealand are Fonterra, NZ Steel, New Zealand Aluminium Smelters (which operates the Tiwai Point Aluminium Smelter), NZ Refining, Golden Bay Cement, Methanex and Pan Pac Forest Products. According to business journalist Rod Oram, for years these companies have been the main beneficiaries of favourable Government policies designed to minimise the impact of the New Zealand Emissions Trading Scheme on companies which are emissions intensive and trade exposed (EITE). In 2017 these companies (plus another three of the largest emitters) received 90% of the free credit allocations—essentially a licence to continue polluting—offered by the Government under the scheme.
Households