Key findings included projections air temperature would increase by up to 3.4 degrees, annual rainfall by up to 12 percent, and wind speed by as much as 3.7 percent – all by the year 2090.

The snowline could also rise 400-670 metres by that time, with an expectation snow volume would decrease up to 50 percent by 2050.

The 669-page assessment from Earth Sciences New Zealand (ESNZ) was discussed at a recent Environment Southland meeting where council staff presented a summarising paper.

Southland Regional Climate Change Working Group co-chair Phil Morrison said the "complex" report confirmed the trajectory of the changing climate.

“The relatively benign climate we’ve enjoyed in the past, it seems that we will be challenged to a far greater degree in the future with a less benign climate,” he told Local Democracy Reporting.

Morrison said scientists often used averages to talk about the changing climate but it was his experience that the extremes were the bigger concern.

The report identified a range of risks including warmer waters increasing disease susceptibility for wild fish and aquaculture, and the expansion of warm water pest fish.

Hydro power generation could be impacted by a reduction of snow melt in spring and summer, while reduced snow cover posed a problem for the ski industry.

There were also threats to roading, such as sea level rise and storm surges affecting coastal roads and high temperatures damaging bitumen.

Stormwater and wastewater pressures were also identified, with wildfires a consideration.

Opportunities identified by the report included longer growing seasons, new crops, stable or increased flows for hydro in western catchments, and better summers for the tourism industry.

The 2026 Murihiku Southland Climate Change Impact Assessment is split across four volumes and provides an update to its 2018 predecessor.

It was due for completion in June 2025 but was delayed due to NIWA transitioning to ESNZ and issues with a supercomputer.

Morrison noted that between 2023 and 2025, the amount of people who actively disagreed with the concept of a changing climate had dropped by 3-4 percent, according to local surveys.

LDR is local body journalism co-funded by RNZ and NZ On Air.