New Zealand’s future amid climate change is projected to be warmer and drier than previously anticipated, according to new forecasts. A recently released interactive national map presents the most detailed overview yet of how the country’s climate is expected to change throughout this century.
The modelling, led by Niwa, indicates that depending on the speed and effectiveness of global emission reduction efforts, New Zealand’s average temperature could increase between 0.8°C and 3°C by 2090.
Most regions are also expected to experience a significant rise in the number of extremely hot days, defined as days when temperatures exceed 25°C.
In Auckland, such temperatures were recorded about 20 days per year during the 1995-2014 period, which serves as the baseline for the new modelling comparisons.
Based on the latest mid-range projections, Auckland could see an increase of an additional dozen hot days by 2040, 24 more days by 2060, and 48 more days by 2099.
In addition, the city’s average summer temperature could rise by as much as 1.7°C by 2050 and up to 3.6°C by 2090. By that time, Auckland may also experience a slight decrease in annual rainfall along with an increase in dry days.
In contrast, Wellington is projected to become slightly wetter by 2090, with the most significant changes occurring during the summer, where seasonal rainfall could rise by between 1.7% and 10.6%. Wellington is also expected to experience warming, with temperature increases ranging from 0.7°C to 2.8°C.
In Christchurch, the number of hot days could increase by anywhere from 4.6 to 46.6 by 2090, with average summer temperatures projected to rise between 0.9°C and 3.3°C by the end of the century.
Other projections for major centers by 2090 include an increase of 9.5 to 77.8 hot days in Hamilton, a decline in annual rainfall of 9.8% to 18.2% in Tauranga, and an additional 1.2 to 42.7 hot days in Dunedin.
On a broader scale, the projections suggest a decrease in annual rainfall across the North Island, particularly in the north and east, while the west and southern regions of the South Island may see increased rainfall.
In Westland, one of New Zealand’s wettest areas, winter rainfall could rise by 1.7% to 24.7% by 2090 compared to the baseline period.