Climate Change in Aotearoa

Many people live on or near the coast in Aotearoa and will be affected by sea level rise. Image: LEARNZ.

The Earth has had many tropical climates and ice ages over billions of years. So why is now so different? Well, as you will have read in What Is Climate Change, human activity over the last 150 years has led to us releasing larger amounts of greenhouse gases into the Earth’s atmosphere over a short period of time leading to more rapid climate change.

Aotearoa is already experiencing higher land and sea temperatures, and more severe storms.

How will climate change affect Aotearoa?

Our changing climate will affect our economy, environment and way of life. Based on the latest climate projections for Aotearoa, by the end of this century we are likely to experience:

higher temperatures
rising sea levels
more extreme weather events
changes in rainfall patterns

Sea level rise and glacial retreat

The sea rose 14 to 22 centimetres in the last century. By the end of this century sea level is expected to be around 80 centimetres higher than it is now.

The oceans are becoming slightly more acidic by absorbing more CO2. Even though this increase is small it can affect sea creatures, especially those that have a shell which can be damaged by the increase in acidity.

Our glaciers have lost a quarter of their ice in the past 40 years. Glacier loss will impact ecosystems, severity of flooding, and supplies of fresh water for drinking, agriculture and hydropower generation.

Climate change will lead to increased glacial recession affecting drinking water supply, agriculture and hydropower generation. Image: LEARNZ.

Hotter, dryer, warmer, and windier!

Some regions will have less rain. This makes soils dry out and increases the need for irrigation. Some regions will also have less frosts, and more warm days.

What will warmer temperatures mean for farmers?

Higher temperatures

There is likely to be an increase in demand for water, air-conditioning systems (for classrooms too!) and therefore more electricity in summer. People are likely to enjoy the benefits of warmer winters with fewer frosts, but hotter summers will bring increased risks of heat stress and subtropical diseases.

Flooding

More frequent intense winter rainfalls will increase the likelihood of rivers flooding and flash flooding. Our drainage systems have not been designed for these extreme rainfall events.

Water resources

Water demand will increase during hot, dry summers. Longer summers with higher temperatures and lower rainfall will reduce soil moisture and groundwater supplies. River flows are likely to be lower in summer and higher in winter.

Sea-level rise

Rising sea levels will increase the risk of erosion, inundation and saltwater intrusion. There will be a need for coastal protection where it is possible.

Health

Higher levels of health-related issues because of summer heat could be expected. Mosquito species that carry diseases like malaria may also settle in Aotearoa in a warmer climate.

Built environment

A city is usually hotter than rural areas. This effect is called an Urban Heat Island. Warmer temperatures can make it more unpleasant for people living there.

Transport

Hotter summers can damage railway lines and soften road surfaces.

Agriculture

As some areas warm, food production might increase. But higher temperatures will also bring pests, and drought will affect farming. There may not be enough water to sustain irrigation in some areas.

Business and finance

People living on floodplains might find it more difficult to insure their homes due to higher flood risk. Fruit and vegetable growers might lose more crops to hail damage resulting in a loss of income.

Climate change will affect agriculture, frequency of flooding and droughts, and vulnerable ecosystems. Image: LEARNZ.

How will climate change affect wildlife?

In Aotearoa, our native species and ecosystems will be affected in different ways by climate change, depending on where they live.

Alpine Ecosystems are refuges for many bird, lizard and insect species. As temperatures rise, pests like hedgehogs, rats and wasps will spread into higher areas.
Freshwater ecosystems are at risk because they are already under pressure from high levels of land use and water take for irrigation and may not be able to cope with further stress as average temperatures increase.
Coastal Ecosystems will be eroded by rising sea. Storm surges and sediment will affect mudflat areas.
Vulnerable native species may not be able to adapt to a changing environment. They may need our help, such as relocation or building structures for nesting sites.
Wildfire can often leave land bare. If left, this can lead to erosion, land slumps, and sediment that pollutes waterways.