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How we track our city emissions

In order to reach our net zero climate action targets, we need to regularly and accurately measure a variety of emissions across the city.

Wellington’s gross emissions reduced by 10% between 2019/2020 and 2022/2023. In the 20 years before that, gross emissions reduced by 8%, even while the population grew 24%.

We need to continue to reduce our carbon at similar or faster rate to reach our commitment of making 57% reduction by 2030 and being net carbon zero by 2050. To do this we need to make our biggest reductions over the next 7 years. 

City Emissions Inventory

Our city's emissions inventory was periodically conducted for the calendar years 2014, 2016, and 2019. However, starting in 2020, our inventory has been calculated annually for financial years.

In 2023, our city emissions inventory was calculated for financial years 2022/23.

Wellington City Community Carbon Footprint Report 2022/23 (1.2MB PDF)

Wellington City Greenhouse Gas Inventory COVID-19 impact assessment (952KB PDF)

Transport is the largest source of our city’s total emissions (56%) followed by stationary energy such as electricity and natural gas use in buildings (28%). To achieve our city’s 2030 emissions reduction target, we need to make significant reductions in these two key emissions sources over the next 7 years by changing how we live and move around the city.

Pie chart showing the city emissions breakdown. Transport is the largest 56.2%, Stationery energy 28.3%, Waste 7.3%, Industry 6.6%, Agriculture 1.6%.

Emissions breakdown

In the 2023 reporting year, Wellington City emitted gross 887,155 metric tonnes of carbon dioxide equivalent (tCO2e). 

  • Transportation is the biggest source of emissions accounting for 56.2% of total gross emissions. 
  • Stationary energy is the second largest emitter, 28.3% of total gross emissions. 
  • Waste (7.3% of total gross emissions), industry (6.6% of total gross emissions) and agriculture (1.6% of total gross emissions) are the smaller sources of emissions in Wellington City.

What emissions are measured

The Wellington city greenhouse gas emissions inventory aligns with the Global Protocol for Community Scale Greenhouse Gas Emissions Inventories (GPC).

The report accounts for greenhouse gas emissions of sectors within the city boundaries. These sectors are:

  • Stationary energy – includes emissions from electricity and natural gas.
  • Transportation – includes emissions from on and off-road transportation (petrol and diesel), rail, air, bus electricity, LPG, and port activities.
  • Waste – including waste originating in Wellington City from both solid waste (open and closed landfills) and wastewater.
  • Industry (industrial processes and product use) – including emissions of synthetic gases used in activities such as refrigeration, air-conditioning, fire extinguishers, aerosols, and electrical equipment production.
  • Agriculture – from within the city boundaries.

The gross total is then adjusted to reflect emissions sequestered (removed) through forestry, which provides the net emissions.

Did you know? Carbon sequestration is the process of capturing and storing carbon dioxide from the atmosphere. This is often done by planting trees and forests.

What emissions aren't measured

This inventory does not include emissions from products created outside of Wellington's boundary. For example, concrete production is high in emissions but is made outside of Wellington before being trucked in to create a new building or footpath, so it wouldn't be included.

The emissions associated with goods purchased and consumed by Wellingtonians are not included in our inventory but do need to be considered. Future city inventories may include more data from the 'stuff' we buy that wasn't made in our city.

Find out more about our Te Atakura action areas and initiatives, and five ways to take climate action.