KEY POINTS:
New Zealand will increasingly be hit by heavy rainfall causing flooding, landslides and erosion, says a draft report into the effects of future climate change.
The Weekend Herald was yesterday told some of the key findings in the report of the Intergovernmental Panel on Climate Change (IPCC) affecting New Zealand.
Entitled "Impacts, Adaptation, and Vulnerability", the report is due for release after finalisation in Brussels next week.
It predicts significantly increased rainfall in most of New Zealand - except for the east of the North Island and the north of the South Island - and consequences such as landslides.
The report predicts warming of 0.2C to 1.3C by the 2030s, and from 0.5C to 3.5C by the 2080s.
It says New Zealand is already experiencing impacts from recent climate change and noted the 2004 North Island floods cost about US$78 million ($109 million).
It used the Bay of Plenty as a case study to show that while beachfront properties there demanded the highest premiums on the property market, they faced the highest risks of future flooding, storm surge and erosion in the region.
Aileen Lawrie, coastal planner for Environment Bay of Plenty, was not surprised, saying the regional council had already identified 1000 coastal properties at risk from those hazards within a 100-year timeframe.
When property owners planned to replace existing structures, they were being encouraged to build relocatable dwellings, and the council was not allowing future development in high-risk coastal areas.
The IPCC report said it had "high confidence" in its scientific findings of stresses on agriculture and changes to natural ecosystems in response to climate change.
It forecast reduced seasonal snow cover and shrinking glaciers. New Zealand's snow line was likely to rise by 120m to 270m based on scenarios for the 2080s.
Changes in seasonal snow cover were likely to have a significant impact on the ski industry, but that could be partly offset by increased tourist flows from Australia given relatively poor snow conditions there.
Shrinking glaciers would mean fewer visitors to West Coast towns.
Mike Smith, marketing manager of Ruapehu Alpine Lifts, said there was already evidence of rising snow lines but still a lot of volatility in seasonal snowfalls.
Mr Smith said snow-making technology and management was keeping ahead of climatic shifts. "A snow line rise of 200m would mean very little."
The IPCC indicated both positive and negative impacts of climate change on forestry.
Growth rates for plantation forests were likely to increase in the south and west of the country.
However, a reduction in tree growth was predicted for the eastern North Island from rainfall decreases, and the warmer and drier weather could increase the frequency of upper mid-crown yellowing and winter fungal diseases.
The kiwifruit industry would suffer delayed bud break and reduced yields. In Northland, the production of current varieties was likely to be uneconomical by 2050 because of a lack of winter chilling.
Dave Kelly, a Kerikeri kiwifruit grower, said substantial breeding programmes were underway.
"I'd be surprised if we were growing the same varieties in 40 years ... we will adapt."
