Climate Changes Impacts and Implications
CCII (Climate Changes, Impacts & Implications) was a targeted research project aiming to update and improve projections of climate trends, variability, and extremes across New Zealand out to 2100, based on the latest global projections. It generated new knowledge about the potential impacts of climate change and variability on New Zealand’s environment, including our natural ecosystems and native species, and the impacts on the many productive activities which depend on the environment and enable continued growth and prosperity.
The project comprised five inter-related research aims:
Bodeker Scientific and NIWA worked on Research Aim 1, combining validated data from the National Climate Database, output from NIWA’s core-funded regional climate modelling, and the latest global modelling from the CMIP5 activity in support of the IPCC 5th assessment report (AR5), to develop downscaled projections over New Zealand for a range of climate variables that are consistent with global trends. The key results are summarised in the RA1 synthesis report.
The goal was to generate data sets and associated maps of changes in climate extremes from 1971 to 2100. We also used a newly developed approach (Lewis et al. 2017), based on pattern scaling principles, to incorporate model structural uncertainties, in addition to greenhouse gas emissions scenarios, in the assessments of changes in extreme events.
Specifically, we produced data sets and maps of:
Frequency of hot days (days above 25°, days above 30°),
Frequency of frosts (days below 0°, days below -2°),
Frequency of hot spells (5+ consecutive days with Tmax >25° or 30°)
Length of hot spells (number of consecutive days with Tmax >25° or 30°)
Frequency of cold spells (5+ consecutive days with Tmax < 10° or 15°)
Length of cold spells (number of consecutive days with Tmax < 10° or 15°)
Frequency of wet days (days above 1mm, 10mm, or 20mm)
Frequency of wet spells (5+ consecutive days with > 1mm on each day)
Frequency of dry spells (15+ consecutive days with < 1mm on any day)
Lewis, J., Bodeker, G. E., Kremser, S., and Tait, A.: A method to encapsulate model structural uncertainty in ensemble projections of future climate: EPIC v1.0, Geosci. Model Dev., 10, 4563–4575, https://doi.org/10.5194/gmd-10-4563-2017, 2017.