“This 22 km3 decrease between 2005 and 2023 is equivalent to 37 percent of the volume of Lake Taupō,” environment statistics spokesperson Tehseen Islam said.

Stats NZ has updated its Annual glacier ice volumes: Data to 2023 environmental indicator, using data from the National Institute of Water and Atmospheric Research (NIWA).

Glaciers support power generation, primary production, and water resources. They regulate downstream water temperature, which is important for many aquatic species, including taonga species.

Glaciers are highly sensitive indicators of the earth’s surface energy balance, which is the exchange of energy between the sun, the atmosphere, and the earth’s surface.

“Changes in glacier volumes are important indicators of climate change,” Islam said.

Melting glaciers add to coastal erosion and sea-level rise, further contributing to the impacts of climate change. Ecological and hydropower resources downstream can also be affected by changes to ice storage and melting.

Between April 2022 and March 2023, ice volumes decreased by 6.5 percent, or 2.1 km3, which is equivalent to 3.6 percent of the volume of Lake Taupō.

The environmental indicators Wildfire risk: Data to 2023 and UV intensity: Data to 2023 were also published.

Stats NZ publishes and updates environmental indicators on the state of, and pressures and impacts on, New Zealand’s environment including air, marine, fresh water, land, and atmosphere and climate as part of a joint Environmental Reporting programme with partner Ministry for the Environment.