Figure 3.2: New Zealand temperature (in °C) – historical record, and schematic projections illustrating an example of future year-to-year variability (upper panel) and the full range of multi-decadal warming over the IPCC emissions scenarios (lower panel)

Text description of figure

This figure has 2 panels, both showing New Zealand national average temperature from 1908-2100 in degrees Celsius deviation from the 1980–1999 mean. The upper panel shows the year-to-year variability. For the observed period (1908–2006) the temperature shown is the average over seven long-term NIWA climate stations.

For the schematic projection period (2007–2100) the temperature shown is the national-average of year-by-year downscaled temperatures from one of the IPCC Fourth Assessment models.  

The figure illustrates that if the future year-to-year variations are comparable with current ones, the rising mean temperature will mean that towards the end of the period (2100) even the coldest years are warmer than any experienced up till now.

The lower panel shows the data smoothed to illustrate the decadal variations. The linear extrapolation to 2100 of the observed temperature trend from 1908 to 2006 is also shown. Vertical bars at 2040 and 2090 represent the full IPCC range of New Zealand warming in the 6 IPCC emission scenarios, which for both periods is much larger than the decadal variations and lie almost wholly above the linear trend line.