1. Climate change and PNG Agriculture Presentation: PNG Update 14 June 2018
Dr Mike Bourke OL (PNG)
College of Asia and the Pacific
The Australian National University, Canberra

2. Greenhouse effect Our planet is a natural greenhouse
Keeps temperatures relatively stable
Now more CO2, methane and N20
Extra atmospheric gas from human activity
CO2 from fossil fuel, loss of forests
Methane from rice cult., sheep, cattle
Extra gases result in heating, sea level rise and changes in climate

4. Evidence for climate change in PNG
Temperature increase in highlands greater than global mean (1.0 oC/30 years)
Sea level rise (coastal; islands)
Changes in rainfall, especially seasonal
Some locations wetter; others dryer
Possible increase in cloud cover

6. Crop altitude data
Comprehensive dataset on the altitudinal range of 230 crop species available
Data mostly recorded in 1979 to 1984
Changes in altitudinal limits is a surrogate for temperature change
Bourke, R.M. (2010). Altitudinal limits of 230 economic crop species in Papua New Guinea. In S.G. Haberle, J. Stevenson and M. Prebble (eds). Altered Ecologies: Fire, Climate and Human Influence on Terrestrial Landscapes. Terra Australia 32. ANU E-Press, The Australian National University, Canberra. pp

8. Evidence for temperature increase in PNG highlands
1. Increase in recorded temperature, Aiyura
2. Coconuts in highlands bear nuts up to:
1310 m (1979)
1450 m (1999)
1560 m (2009)
1620 m (2015)

9. Impact of sea level rise in coastal areas of PNG
Widespread anecdotal evidence, including:
coastal erosion on most islands
loss of coastal land
relocation of villages
sea level intrusion to fresh water lens on atolls (eg Mortlock Islands, AR Bougainville)
damage to swamp taro (Cyrtosperma)

10. Impacts of CC on rainfall and cloud cover in PNG over past 30 years
Changes in rainfall patterns
Complex pattern
Seasonal changes (since late 1980s)
Some locations wetter; others dryer
Longer data runs needed
Possible increase in cloud cover

11. Likely impacts of climate change in coming decades
Impact from:
Sea level rise
Temperature increase
Rainfall (total and seasonal)
Cloud cover
Changes to El Nino/La Nina frequency?

12. Most vulnerable environments to impact of climate change
Analysis of most vulnerable environments:
Atolls (sea level incursion/coastal erosion)
Other small islands (>100,000 people)
Central highlands ( m asl)
V. high altitude highlands ( m)

13. Vulnerability of highlands
Highlands ( m) excellent environment for agriculture
Temperatures optimal for soil organic matter breakdown and nutrient release
Temperatures at m changing to those at m
Changing to much poorer environment
Consequences for agricultural production

14. Population by altitude

15. How to reduce impact of CC
Limited migration to other locations
Increase cash income for villagers
New food crops (very few available)
Greater availability of relatively fast maturing crops (corn, sweet pot., potato)
Cultivars more tolerant of rainfall extremes
Especially sweet potato, banana, taro, yam, corn, cassava, potato

16. Em tasol