Step 3: Find Existing Climate Change Information

A literature and internet search reveals that there is some useful general information about growing root vegetables in PNG, including the Pacific Community (SPC) book chapter by McGregor et al. (2016).

A detailed analysis of the climate envelope for growing root vegetables in PNG that includes maps has not been produced before, so there is some room for new analysis. The temperature and rainfall thresholds of the climate envelope for root vegetable growing are fairly well known. We are interested in looking at thresholds, and the upper threshold for taro, yams and cassava are fairly high and unlikely to be reached in coming decades (McGregor et al. 2016). The correlation between the spread of taro leaf blight with increasing minimum night time temperature is well studied (Bourke 2013), and would be a worthwhile case study.

Here we choose to look at two important and well-studied thresholds for sweet potato:

  • Tuber formation is impaired when air temperature exceeds 34 °C (Bourke 2013)
  • Minimum growing temperature is 10 °C.


Bourke RM. 2013. Implications of climate change for food security in Papua New Guinea. Report prepared for the Australian Department of Climate Change and Energy Efficiency. Canberra, Australia.

McGregor A, Taylor M, Bourke RM, Lebot V. 2016. Vulnerability of staple food crops to climate change. Vulnerability of Pacific Island agriculture and forestry to climate change. M Taylor, A McGregor and B Dawson. Noumea Cedex, New Caledonia, Pacific Community (SPC): 161–238.