Step 5: Collect and Evaluate Climate Model Data
We need change factors between a baseline period and future periods for the variables of mean annual daily maximum temperature and daily minimum temperature.
We need results for all the emissions scenarios (here we look at the representative concentration pathways or RCPs) to illustrate the risk under each one and to show the benefit of mitigation.
Temperature change is fairly uniform in space, so we can use a single change value for all of PNG (spatial datasets including high-resolution downscaling could be investigated as a follow-up study).
The ranges of change from the PNG chapter in the PACCSAP report (Australian Bureau of Meteorology and CSIRO, 2014) meet all these requirements. The PACCSAP results use a group of CMIP5 global climate models that have been evaluated and three unsuitable models were rejected (Grose et al. 2014). They cover a range of projected change that are plausible, and values are available for all the RCPs for various time periods.
Australian Bureau of Meteorology and CSIRO. 2014. Climate variability, extremes and change in the western tropical Pacific: New science and updated country reports. Pacific-Australia Climate Change Science and Adaptation Planning Program technical report, Melbourne, Australia. Available at www.pacificclimatechangescience.org
Grose MR and co-authors (2014). Assessment of the CMIP5 global climate model simulations of the western tropical Pacific climate system and comparison to CMIP3. International Journal of Climatology, 34: 3382–3399