Climate Change


The Deep South Science challenge is one of 11 national science challenges; these challenges are a 10 year, multi-million dollar investment tackling New Zealand’s hi-tech challenges to grow our economy.

The Deep South National Science Challenge is working to understand the role of the Antarctic and Southern Ocean in determining New Zealand’s future climate, and the impact this role has on key economic sectors, infrastructure and natural resources. This will enable New Zealanders to adapt, manage risk and thrive in a changing climate.

The project is split with a mid-project review occurring in 2019. Research funding for individual sub projects has a maximum period of five years.

There are five main programmes within the Deep South Challenge and multiple sub-projects within each programme.

Earth System Modelling and PredictionThe focus of this programme is to assemble the first New Zealand Earth System Model (NZESM), which will sit in the heart of the Deep South Challenge work. An Earth System Model combines the physical processes of atmospheric and oceanic circulation with the chemical and biological processes that impact the Earth system.

EngagementThis is a two-way engagement programme between the New Zealand communities, industry sectors, central and local government, and the science researchers.

Vision MātaurangaThe Deep South Challenge is applying the MBIE Vision Mātauranga objectives through strategic planning and research. These efforts will contribute innovative, practical and sustainable solutions for Māori and all New Zealanders.

Processes and ObservationsThe aim of this programme is to improve our understanding of the global climate system by observing processes in Antarctica, the Southern Ocean, and the atmosphere.

Impacts and ImplicationsIf we can understand how climate change will impact New Zealand, we can plan for it more effectively. This involves taking a ‘big picture’ view. We need to explore how the many and varied impacts of climate change will interact with each other.

We’re also aiming to make sure communities, end-users and stakeholders consider climate change in multiple contexts and make robust decisions about adaptation.

Further, we need to better understand the institutions that facilitate climate change adaptation. Our research is looking into historical responses to environmental threats and at the way climate-sensitive decisions are currently being made.

It is the results from Impacts and Implications stream that will be of most concern to the New Zealanders associated with the 3 waters sector. Other than the obvious implications from sea level rise, with defend or retreat options versus adapting to changing coastal areas, and economic implications such as escalating insurance costs, there are a number of other implications that need to be considered, such as changing climatic conditions, the potential diversification of our agriculture, loss of natural fauna and flora.

The potential implications of climate change reach far further than the coastal areas of New Zealand. The west side of New Zealand can expect an increase in intensity and frequency of participation events, whereas the east can expect a decrease. Weather patterns will be more extreme with more intense rainfall in places and longer droughts in others, ground water levels may become more seasonal and lightning storms more common.

Some of the potential implications for the 3 waters sector may be as follows.

For stormwater

  • Reduction in gradients affecting low lying coastal areas.
  • Lower level of service with existing stormwater service due to higher intensity rain events.

For wastewater

  • Higher inflow and infiltration, both from higher inland ground water levels and from more intense and frequent rain events.
  • Increase in hydrogen sulphide in coastal areas due to salt water intrusion.
  • Reduced wastewater flows in times of drought.
  • Relocation of low lying waste water facilities.

For drinking water

  • Increase in raw water storage due to increase in drought conditions.
  • Higher cyanobacteria issues with a change in temperature causing an increase in algae growth in dams, rivers and lakes.
  • Higher risk of pathogens with increased rain events in winter and less dilution of animal waste during summer. Most pathogenic bacteria multiply fastest at temperatures close to human body temperature.
  • More emphasis in leakage reduction and demand management with an increase pressure on available raw water.
  • Increased corrosion of steel pipes due to higher ground water levels, perhaps requiring cathodic protection.

Water New Zealand is a member of the representative user group for the Deep South Challenge and sees the need to keep the 3 waters sector informed of the learnings of this science challenge as they become known. Despite Donald Trump’s thoughts, it’s not a case of if climate change will occur, but what is the best estimate of the rate of change

The intention is to have a number of presentations on this topic over the next year to help raise awareness.

Please feel free to contact Noel Roberts for any questions.


Looking away from the rear view mirror: making better decisions in a time of uncertainty - Professor Iain White

Emergent exposure of flood inundation hazards under future climate change in New Zealand - Ryan Paulik, NIWA Wellington, Scott Stephens, NIWA Hamilton, Daniel Collins, NIWA Christchurch, Rob Bell, NIWA, Hamilton, Gabriella Turek, NIWA Wellington, Sanjay Wadhwa, NIWA Hamilton


Climate Change and Stormwater and Wastewater Systems

We know climate change is happening and we know stormwater and wastewater systems are vulnerable. What we don’t know is how these impacts will unfold over varying places and times. This discussion paper provides an overview of our current knowledge, and outlines priority research areas to help adapt our stormwater and wastewater systems for a changing climate. The paper draws on a range of expert input, including academia and Crown Research Institutes, the public and private sectors, and specifically water service providers and consultants. Research priorities are: to understand direct and indirect impacts, to identify adaptation opportunities within redevelopment and retrofit, to explore solutions to reduce dependence on legacy delivery mechanisms, and to identify potential improvements in stormwater risk management.

Find out more here.