About Climate Change | Climate Impacts
Climate change is having, and will have, a range of physical and environmental impacts (for example, sea-level rise, rising temperatures and changing pest profiles). Adaptation is about trying to reduce or overcome the way these impacts affect our human, economic and built systems.
Good adaptation planning is based on up-to-date information about climate impacts in your local area. This section highlights our/current research into climate impacts, and gives you some brief information about individual impacts.
These resources can help you explore data and analysis about a range of climate impacts. You can also access some localised or case study information. As well, you can learn how to access or ask for data that's relevant to your specific location.
We have enough information about climate impacts to begin adaptation planning now.
We have already experienced around 20cm of sea level rise since humans began burning fossil fuels at an industrial scale. This has been enough sea level rise to cause significant flooding and inundation issues on some parts of New Zealand's coastline, which has been developed without sea level rise in mind.
Seas are expected to rise at an increasingly fast pace. New Zealand's seas are rising at a faster pace than elsewhere around the world.
We expect another 30cm or so by 2050 and, if we don't curb carbon emissions, between 1m and 1.2m by the end of the century. Storm surges, especially when they coincide with high tides, could push the levels much higher.
By 2100, a one-in-100-year coastal flood will be likely every few months, and roads, properties and all kinds of built infrastructure within 200 metres of the current coastline will be vulnerable to inundation and damage. The sea will continue to rise beyond 2100 as well.
Without adaptation, we will see low-lying suburbs in Auckland and Wellington under water.
Flooding is the most immediate and (along with drought) costly climate impact we are experiencing in Aotearoa.
Sea level rise, coupled with extreme rainfall and big storms, make both coastal and river flooding more likely.
Under the average of all sea level rise scenarios, our modelling suggests that around 7,000 buildings nationwide become exposed to coastal flooding for every 10cm the sea rises. We expect at least 30cm of sea level rise by 2050. With 1m of sea level rise almost certain by 2100, the nation's assets that are exposed to coastal flooding with double or triple.
Flooding along rivers will also increase as extreme rainfall events get worse. Currently, about 675,000 people and over 400,000 buildings worth $135 billion are exposed to river flooding following storms and heavy rain.
It is possible to deal with flood risks. Solutions include not building in flood-prone areas, shifting away from places that keep flooding, as well as engineering solutions like seawalls and stop-banks. Other options include rejuvenating beaches and restoring sand dunes coastline ecology. We can both embrace the coast and plan our retreat from the edge.
Extreme weather reveals the true power of Papatūānuku – our planet. Those parts of the world that experience tropical cyclones (hurricanes) and tornadoes can be flattened by the wind, and devastated by the massive flooding from extreme volumes of rain.
In Aotearoa, we’re fortunate not to experience tropical cyclones directly. Nevertheless our weather is highly dynamic. Extreme wind and hail can be very damaging, and extreme rain leads to flooding and landslips, which can leave whole regions cut off because of the relatively few roads in and out of many parts of this country.
A warmer climate holds more moisture, with the potential to deliver significantly heavier rainfalls. Models and observations also suggest that rainfall patterns are changing. Our extremes are becoming more extreme, but also more spread out, so that at the same time, there is generally more drought as well.
Modelling suggests that with 1.5 and 2 degrees warming, rainfall extremes may become heavier in New Zealand’s west and lighter in the east, especially in the South Island.
Landslips and erosion are perhaps not well-understood as "climate" impacts. Yet extreme rain events, more likely under climate change, increase the risk of landslips. The higher the rainfall intensity, the more landslides happen.
The extent to which land is vulnerable to landslip depends on many factors, including its slope and elevation, the quality of the drainage and the quality of the soil. Some of our research suggests that more than 70% of weather-related EQC claims are most likely related to landslips. There are currently no national rainfall-induced landslip hazard maps.
Drought already impacts a wide range of activities in Aotearoa, including urban water, primary production and electricity generation. It also has significant cultural impacts across communities.
Although New Zealand has historically been “water rich”, we are not well-prepared to cope with a future of more drought in some areas. Treasury estimates that drought is the most costly climate impact we face.
As climate changes increases, water supply systems will have to adapt, which may include new sources, new technologies, increased storage capacity and better management of water use. We need to adapt our water systems far enough in advance to avoid running out of water in the future. In many cases, the planning process needs to start now.
Fire risk and fire intensity are also expected to increase, particularly in the east, due to warmer, drier and windier conditions. Learning how to protect your home and your whānau against wildfire is a form of climate adaptation:
- keeping a plant-free perimeter around your home
- store firewood in a cool, dry place away from the house
- have a well-practiced community emergency plan.
Our oceans are getting warmer and more acidic.
In recent summers, New Zealanders have experienced a series of marine heatwaves, with temperatures in some regions reaching 6°C above average.
Because we’re an island nation, ocean temperatures have a big influence on our climate and our climate extremes (such as droughts, floods and tropical storms). Marine heatwaves in the Tasman Sea, for example, can result in atmospheric heatwaves and climate extremes over New Zealand. Marine heatwaves also affect our kaimoana and have serious implications for the fishing and aquaculture industries (such as mussel or salmon farms).
Ever-increasing carbon dioxide in the atmosphere is also changing our oceans. More than a quarter of the carbon dioxide released into the air by human activity is absorbed by the world’s oceans. This helps buffer global climate change but also causes seawater to become more acidic, threatening the delicate balance of life in our oceans.