Hawke's Bay faces a growing threat from flooding as the climate changes, a top scientist has warned.

Andrew Tait, principal scientist at Niwa, specialising in climate applications, gave the warning this week during a briefing to council staff on the region's weather patterns.

Dr Tait was in Hawke's Bay to present an update of Niwa's Blue Book - an analysis of the region's climate and weather patterns.

He also discussed the local findings and implications of a key international report released last month by the Intergovernmental Panel on Climate Change.


The IPCC report said the effects of climate change are beginning to be felt in every part of the world yet countries are ill-prepared for potentially immense impacts on food security, water supplies and health.

The report, the most comprehensive study yet into the effects of rising levels of carbon dioxide in the atmosphere, warned global warming could undermine economic growth and increase poverty. It found the impacts of climate change have already extended beyond any potential benefits of rising temperatures and will worsen if global-average temperatures rise by the expected lower limit of 2C by 2100 - and become potentially catastrophic if they rise higher than 4C.

A local finding of the report was that areas including Hawke's Bay can expect more heavy rainfall resulting in flooding problems becoming more significant in the decades ahead, Dr Tait said.

New Zealand already had an "adaptation deficit" when it came to dealing with weather events, he said.

"We're badly impacted by flooding and heavy rainfall events already throughout the country and definitely in this region.

"We don't cope well already with these types of extreme events, let alone an increase in them," he said.

"With longer-term warming, particularly if we get the higher-end of those [IPCC] scenarios - changes of 4C by the end of the century - then we are really starting to increase our risk to a very high level."