Climate change report: Act now, or face flood and fire

New Zealand would be increasingly vulnerable to serious events like major floods if the predicted temperature rise happens. Photo / Brett Phibbs

New Zealand is being warned to prepare for floods, droughts and fire over the next century as a result of climate change and global warming.

The outlook comes from the Intergovernmental Panel on Climate Change (IPCC) whose key findings on impacts were released yesterday in a worldwide series of regional briefings.

The IPCC was formed in 1988 to provide scientific advice on climate change and assesses current knowledge in six yearly reports.

Dr David Wratt, a review editor and leader of Niwa's national climate centre, said in Auckland that the IPCC was an impartial body and "not trying to prove anything", allowing the science to speak for itself.

It involved over 1200 scientific authors and 2500 expert reviewers from more than 130 countries, and in a report this year concluded that global warming was indisputable and "very likely" to be man-made.

Dr Wratt said there was no doubt the world was seeing the effects of climate change caused by human activity since 1750, especially the burning of fossil fuels.

Changes observed in New Zealand since 1950 included a warming in mean temperature of 0.4 degC, a decrease in cold nights and frosts by 10 to 20 days per year, a sea level rise of about 70mm, and a loss of at least a quarter of alpine ice mass.

The report predicted that by 2080 there could be up to a 3.5 degC rise in average temperatures and increased rainfall except in the eastern North Island and the northern South Island.

Dr Wratt said New Zealand was more resilient to climate change than many other countries as it was surrounded by oceans but was nonetheless vulnerable to serious events such as major floods.

The IPCC report identified a need to plan for climate changes but said little research had been done.

There were major implications for New Zealand communities including the costs of injury and trauma due to increased storm intensity and higher extreme temperatures, degraded beaches due to sea levels rising and larger storm surges.

There were risks to flora and fauna from climate change in alpine zones and freshwater habitats.

Heat-related deaths were likely to double from 14 to 28 people aged over 65 each year.

There could be an increase in agricultural production up to the year 2050 in parts of the country because of higher carbon dioxide concentrations, longer growing seasons and less frost but that would be offset by increased droughts and fire risks in other areas.