Projected regional climate change hazards

The regional climate change projection data below has been compiled by a review of existing scientific papers and reports to provide a high-level snapshot of the projected changes for the National Climate Change Risk Assessment (NCCRA). The seventeen hazards are those selected in the NCCRA (it is not an exhaustive list of climate change hazards). Hazards are based on two RCP projections:

• RCP 4.5 – with a range of mean annual temperature projected across Aotearoa New Zealand of 0.7–0.9 degrees Celsius by 2031–2050 and 1.3–1.4 degrees Celsius by 2081–2100.
• RCP 8.5 – with a range of mean annual temperature projected across Aotearoa New Zealand of 0.9–1.1 degrees Celsius by 2031–2050 and 2.8–3.1 degrees Celsius by 2081–2100.

This information is based on current climate models and projections for New Zealand. RCP4.5 is a scenario that represents a stabilisation of greenhouse gas concentrations by 2100, and could be realistic if moderate global action is taken towards mitigating greenhouse gas emissions. RCP8.5 is described as the high risk scenario, with greenhouse gas concentrations continuing to increase at the current or an accelerated rate. Whilst global emissions are unlikely to continue increasing at current rates to the end of the 21st century, the RCP8.5 projections serve the purpose of defining the upper envelop of likely futures required for high risk impacts.

There is considerable complexity and inherent uncertainty in climate modelling (e.g. the response of the Antarctic ice sheet to increasing temperature signal resulting in increased sea level rise). Additional unaccounted risks resulting from other mechanisms (e.g. positive feedback loops) may result in impacts similar to those projected in the RCP8.5 scenarios, even if the emissions scenario doesn’t play out as projected. Examples of positive feedback loops include the melting of permafrost in Arctic regions, melting ice (e.g. Arctic sea ice) and clouds. 

Thus, using RCP 8.5 projections in adaptation planning may represent a cautious risk adverse approach, while RCP 4.5 remains a more plausible scenario given international pledges to reduce greenhouse gas emissions. 

The projections are subject to change once updated data are released for New Zealand and this website will be updated. It's also likely that zone data will be updated as more regional climate change reports become available.

See the Toolbox Resources page for more information on climate change and projections, and the Arotakenga Huringa Āhuarangi: A Framework for the National Climate Change Risk Assessment for Aotearoa New Zealand for more information on the NCCRA (MfE, 2019).

Subnational climate zones/regions: