Reducing our carbon emissions
We are working to reduce our emissions by 21% for 2025 in support of global efforts to limit climate change.

Our emissions reduction targets

We are a part of the Carbon Neutral Government Programme. The programme’s aim is to make organisations within the public sector carbon neutral from 2025.

To achieve this, we are working to reduce our emissions by at least 21% by 2025, and by 42% by 2030, compared to our baseline year (July 2020 to June 2021). These targets are in line with New Zealand’s efforts to limit global warming to 1.5°C as a part of our commitment to the Paris Agreement.

To meet our reduction targets, we will transition to a low-carbon operating model. This requires us to change the way we do conservation, including what, why and how we deliver.

How we record our emissions and plan reductions

We report emissions as carbon dioxide equivalents (CO2e) to ensure that we include a range of greenhouse gases, such as carbon dioxide, methane and fluorinated gases. We follow the most recent research and methods of measuring and calculating our emissions as they evolve.

We then measure our reduction progress against our baseline – which is our first year of emission records. These were taken between July 2020 to June 2021 and are known as our “base year”.

Improving how we manage our data helps us plan for more reductions. This is because it offers new ways to understand our emissions which can help us to find new ways to reduce them. So we work to improve our data collection and the tools we use to visualise them to support our planning.

Our current reduction goals


Pie chart of DOC emissions (t CO2e) by source 2021/2022

Our three largest emissions sources between July 2021 and June 2022 (2021/22) were:

  • purchased fuels (diesel and petrol),
  • aerial services (A1 Jet and aviation gas), and
  • wastewater.

As a result, we are focusing on what we can do to reduce emissions in these areas.

What we have achieved so far

In 2021/22, we reduced our total emissions by 16% from 11,091 to 9,326 t CO2e, when compared to 2020/21. This was more than our annual reduction target. 

This reduction was despite the addition of multiple emissions sources that were not measured in 2020/21, as well as increases in emissions factors used for our CO2e calculations.

However, this reduction happened at a time when travel was still restricted due to Covid-19, so we expect to see an increase in total emissions in 2022/23.


Graph to show the volume of CO2e emissions by source in 2020/21 and 2021/22
* Staff commute and working from home data was not gathered for 2020/2021

Reduced vehicle emissions

Much of our work is done in remote places. This means we rely heavily on vehicles, vessels and helicopters, which emit a high volume of emissions.

One of our first plans to reduce this was to change our passenger vehicles to lower emissions alternatives. In 2022, 129 battery electric vehicles replaced 148 vehicles that used diesel or petrol.

The reduction in vehicle numbers was made possible by analysing how we were using our vehicles. This allowed us to develop a plan to use our vehicles in an optimal way, so we could use less and meet the needs of our work.

One of the ways we created optimal vehicle use was by applying an upgraded vehicle booking system. This system allows staff to book whole vehicles or the seats within them.

The booking system maximises vehicle sharing and minimises how many vehicles we use. This also enabled us to find and remove vehicles we found we did not need.

Improved data collection

In 2021/22, we improved the accuracy of our reporting. We did this by reviewing and including additional emissions sources.

We also implemented a new financial and asset management system in DOC. This will help to gather better emissions data over the next few years.

We are also working with those who provide supplies or services to DOC to ensure invoices include the information we need to better report on emissions.

Verifying our progress

DOC participates in Toitū Envirocare’s CarbonReduce programme.

The CarbonReduce programme certifies that we have made a complete and accurate record of our greenhouse gas emissions. This is in accordance with international best practice and is accredited by the Joint Accreditation System of Australia and New Zealand.

The programme also certifies that we meet the Toitū Envirocare criteria for committing to further manage and reduce our emissions. See our CarbonReduce commitment certificate (PDF, K).

We measure our emissions each year to track progress of our reductions and develop deeper understanding of where we can focus reduction initiatives.