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Preparing New Zealand for rising seas: Certainty and uncertainty

19 November 2015

Like other countries, New Zealand needs to prepare for rising seas. 

Over many millennia, the Earth’s climate has cycled between ice ages and warm ‘interglacial’ periods. Over the last seven thousand years the climate has been relatively stable, but this is now changing. Increasing concentrations of carbon dioxide and other greenhouse gases in the atmosphere are trapping heat and the climate has begun to respond. One of the major and certain consequences is rising sea level. 

Nowhere in our island nation is far from the sea, and most of us live within a few kilometres of the coast. Houses, roads, wastewater systems, and other infrastructure have been built in coastal areas with an understanding of the reach of the tides and the recognition that storms will occasionally combine with high tides to cause flooding.

However, with rising seas, tides, waves and storm surges will reach further inland than before, resulting in more frequent and extensive flooding. Along some coasts, erosion will increase and shorelines will recede. In some areas, the water table will rise.

The task of planning for sea level rise is challenging on many levels. For a start, it is technically complex, and the size and timing of impacts are uncertain. Perhaps the most difficult aspect is the impact on people’s homes, which for many are not just their homes, but also their financial security.


See the set of regional land elevation maps published for this report



  • Resources

    Preparing New Zealand for rising seas: Certainty and uncertainty (PDF 2.49 MB)
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    FAQs - Preparing New Zealand for rising seas (PDF 134 KB)
    Preparing New Zealand for rising seas – Overview te reo Māori (PDF 3.4 MB)
  • Consultant reports

    The derivation of New Zealand’s monthly and annual mean sea level data sets (PDF 191 KB)
    The effect of sea-level rise on the frequency of extreme sea levels in New Zealand (NIWA 2015)
    Sea-level extremes at four NZ tide gauge locations and the impact of future sea-level rise (Hunter 2015)
    National and regional risk exposure in low-lying coastal areas (NIWA 2015)
  • Related resources

    Changing climate and rising seas: Understanding the science (PDF 1.59 MB)
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  • Media briefing

    The Commissioner gave this presentation on release of her latest report on sea level rise in New Zealand.