The Royal Society has done a useful report on the possible impacts of climate change on New Zealand.
Some reports are very alarmist and talk about 10 metre sea rises, which is near impossible in the next 100 years. They say the likely increase in the next 100 years is around 30 to 110 cms. That is credible as the current rise is around 3 mm a year.
The report usefully looks at key risks such as flooding, droughts etc. By their own admission they don’t focus on potential benefits such as longer seasons for pasture growth, reduced electricity demand in winter etc.