It aims to help them take concrete action on climate change.
People can access the guide here.
It uses data from three decades of the New Zealand Greenhouse Gas Inventory, from other sources such as Air New Zealand and KiwiRail and from independent construction researcher BRANZ.
The 2022 guide includes significant updates to calculations for domestic air travel and for working from home.
The Environment Ministry said having a reduction plan could also identify where efficiencies could be made, and to demonstrate social responsibility.
The guide is not part of any mandatory reporting framework but it supports the government's work to reduce emissions in the public sector.