David Wratt

A lead New Zealand scientist believes renewable energy production can minimise risks associated with climate change, outlining his views yesterday during an Environment Court appeal hearing for the largest wind farm development in the Southern Hemisphere.

National Institute of Water and Atmospheric Research (Niwa) Wellington climate change general manager David Wratt told the hearing for Meridian Energy's proposed Project Hayes development the wind farm could serve as mitigation for potentially dangerous climate change effects in New Zealand.

"Renewable power, including wind power, is one of the key mitigation technologies and practices currently commercially available for the energy sector. New renewable energy power stations are an essential part of New Zealand's emission management response," Dr Wratt's written evidence stated.

New Zealand would get warmer and experience more turbulent weather in the 21st century because of climate change if greenhouse gas emissions were not reduced, he said.

"Floods, landslides, droughts and storm surges are very likely to become more frequent and intense, while snow and frost is very likely to become less frequent.

"A reduction of 50% to 85% would be required in global carbon dioxide emissions in 2050, compared with 2000, in order to maintain an eventual long-term global equilibrium temperature."

Dr Wratt, who is a bureau member of the Intergovernmental Panel on Climate Change (IPCC), said wind speed at 10m above ground level was likely to increase by between 2% and 6% across Central Otago during winter.

He said because of slightly warmer temperatures in the future there would also be less snow and ice to freeze turbines, which rendered them useless for energy production until thawed.

"I don't want to overstate the positive effects [of changes in climate] on the wind farm, but there will be some benefits in the form of more wind and less ice," he said.