Snow, ice and glaciers in our changing climate

Pouakai Plateau Photo by Rakairoa Hori

The impact of climate change on New Zealand’s frozen water resources

New Zealand is projected to warm by 1-4°C during the 21st century. This warming will melt our frozen water resources – our snow, ice and glaciers. However, the scale, area and timing of changes to our meltwater are unclear.

Mountain rivers in both the North and South Islands of New Zealand feed our largest hydro-electric power schemes, and provide critical water for irrigation, especially during drought. Melting snow and ice may also cause increased flooding.

Our aim is to make projections about how runoff from New Zealand’s glaciers and seasonal snow will change into the future. We’ll also be engaging with iwi and with local authorities to determine the specific needs of communities that utilise water flows. This data is crucial for decision makers in government, communities and industry – all of whom rely on this climate-sensitive resource.

This project brings together, for the first time, New Zealand’s leading snow and glacier scientists. We’ll be developing computer models to simulate how snow and ice respond to climate change scenarios. We’ll make projections of future snow and ice cover, and the resultant runoff from alpine catchments. We’ll investigate the future availability of spring and summer meltwater from snow, and probable changes in summer flow as glaciers are lost. We’ll look at extreme weather events, providing some insight into the frequency and likelihood of large snowfall events, for example, or ‘rain on snow’ events which can cause exceptional floods. We’ll also help to identify the extent to which snow and ice melt can ease the effects of drought, and whether this protective effect will continue in the future.

Improved water projections are essential for the development of climate change adaptation policies that can balance both the financial and intrinsic value of water.

Project contacts: 
Andrew Mackintosh, Victoria University of Wellington
Nicolas Cullen, University of Otago
Project budget: $389,213
Project duration: March 2017 — June 2019

This project in the media:
'Massive snow melt' concerning: researchers Radio NZ
South Island snow 'melt-off' in heat could affect power and irrigation NZ Herald
Hot weather having massive impact on New Zealand's 'water tower' glaciers Stuff
When the world's glaciers shrunk, New Zealand's grew bigger
Adapting to New Zealand’s changing climate

Research and findings:
Impact of climate change on New Zealand’s frozen water resources Andrew Mackintosh, Deep South Symposium


Return to the Impacts & Implications programme page
Check out the full list of Deep South Challenge projects

Latest news and updates

Creating a climate-safe Dunedin through community-driven climate action

2018 may well be the year New Zealand gets serious about adapting to our changing climate. Last year, and the start of this one, gave all of us plenty of opportunities to experience a future in which creeping sea level rise and extreme weather – from drought to flood to surprise storm surges – make day-to-day life more precarious and more expensive.

Stormwater, wastewater and climate change: Impacts on our economy, environment, culture and society

In October 2017, the Deep South Challenge released a report into the state of the nation’s storm and waste water infrastructure, in the face of a changing climate. The report garnered significant media attention – not surprising given the infrastructure is currently valued at well over $20 billion.

The Deep South Challenge awards funding to investigate climate-resilient, high-value crops for the whānau of Omaio

The whānau of Omaio in the Bay of Plenty have joined forces with NIWA researchers to explore the viability of climate-resilient, high-value crops for the rohe. The group has won a $250,000 research grant under the Vision Mātauranga programme of the Deep South National Science Challenge to better understand Omaio’s changing climate and how it might support the community to create a local economy based around a high-value product like kiwi fruit.