Water security, natural ecosystems, and coastal communities are the three sectors most vulnerable to climate change in New Zealand, according to an Intergovernmental Panel on Climate Change (IPCC) report finalised in Brussels on April 6th.

Changes already observed since 1950 include:

• A warming in mean temperature for New Zealand of 0.4 °C;
• A decrease in cold nights and frosts by 10–20 days per year;
• Sea level rise of about 70 mm;
• Loss of at least a quarter of alpine ice mass;
• Increased seed production in beech forest.

Referring to New Zealand, the report’s findings include:

• As a result of reduced precipitation and increased evaporation, water security problems are projected to intensify by 2030 in Northland and some eastern regions.
• Sites at risk of loss of biodiversity include the alpine areas and sub Antarctic Islands.
• Ongoing coastal development and population growth in areas such as Northland to Bay of Plenty are projected to exacerbate risks from sea-level rise and increases in the severity and frequency of storms and coastal flooding by 2050.
• Production from agriculture and forestry is projected to decline by 2030 over parts of eastern New Zealand due to increased drought and fire. However, initial benefits to agriculture and forestry are projected in western and southern areas and close to major rivers due to a longer growing season, less frost, and increased rainfall. A southward shift in agricultural pests and diseases is likely with New Zealand becoming more susceptible to the establishment of new horticultural pests.

Dr Jim Salinger of NIWA, who was a lead author of the chapter in the report referring to Australia and New Zealand, says: "This chapter is the product of a comprehensive survey of the science since 2001. It’s based on over 550 research studies of what’s happening in Australia and New Zealand. In addition, over 50 independent experts reviewed the chapter."

"The potential impacts of climate change for New Zealand are likely to be substantial without further adaptation. The most vulnerable sectors are natural systems, water security and coastal communities."

"Apart from natural systems, New Zealand has substantial adaptive capacity to cope with small amounts of climate change. This is due to our well-developed economy and strong scientific and technical capabilities. But there are considerable constraints to implementation and there will be major challenges from changes in extreme events and larger amounts of changes in climate," Dr Salinger says.