Climate Impact Assessment for Southland

2019-05-02T15:54:00 Pacific/Auckland

Environment Southland’s Strategy and Policy committee today endorsed a report commissioned by all four Southland councils on the impacts of climate change to the region.

The Regional Climate Change Impact Assessment, prepared by the National Institute of Water and Atmosphere (NIWA) provides important data and addresses potential impacts of climate change on a range of components of climate, hydrology and coastal processes across Southland.

Environment Southland policy and planning manager Lucy Hicks said we know that the climate is changing. In order to prepare, robust data is needed to base our decision-making and future plan developments on.

“The changes to our climate will have implications not only for Southland, but New Zealand’s climate and weather systems, for freshwater availability and for our communities’ exposure to hazards,” she said. “Trends will vary across the country and will depend on the level of emissions over the coming century.”

For Southland, we are likely to experience warmer weather all year round, summers will have more dry days and there will be extended periods of relatively higher temperatures. Average annual rainfall is projected to increase, mostly in winter and spring, and is likely to occur in more intense events. Coastal flooding will increase steadily under all scenarios, with increasing incidents of pure tidal flooding (i.e. on sunny days).

Some other general Southland impacts that are highlighted as part of the report include an increase in “severe” event frequency, the size and duration of weather events and there will be more events that are unprecedented.

The report identifies areas where we still need to know more. For example, sea level rise is a highly likely and costly risk for our coastal areas and higher resolution elevation modelling is needed to understand more about this risk.

“The aim of commissioning the report was to provide all Southland councils with access to the best information to address the risks associated with climate change. It will be used by the councils to inform catchment-based planning, to assist in the development of Asset Management Plans and for engagement with communities to help them understand how the range of impacts might affect them.”

Read the full report here.

About the report

The report utilises a comparable methodology to the Climate Change Projections for New Zealand report and the Inter‑governmental Panel on Climate Change scenarios.

The assessment considers two different global warming scenarios (a mid-level warming and a high level warming) that are dependent on the level of emissions over the next century. The combination of climate models and warming scenarios provides for a plausible range of future climatic responses.

Natural climate variability is always present and may add to, or subtract from, the climate change effect. The resulting potential impacts of climate change are presented through averaging of the model projections, which reduces the underlying natural variability to some extent.

The projections represent likely changes in climate relative to a model of the present climate. The present day model closely approximates Southland’s actual climate records collated in 2013. The purpose of the projections is to enable forward planning around a range of possible options for dealing with the impacts of climate change. The intent is for the community to be enabled to be prepared for significant impacts and as far possible develop no regrets policies for future resource management.

Page reviewed: 02 May 2019 3:54pm