Food shortages are associated with droughts, floods, frosts and ENSO in Papua New Guinea

In Papua New Guinea extreme climate events have occasionally led to the collapse of normal subsistence food production systems causing large scale food shortages that threaten human health and survival (e.g. during the 1997 El Niño drought). Production of staple foods (e.g. sweet potato) and cash crops (e.g. coffee) are adversely affected by drought, water logging and frost. We investigated the association between El Nino Southern Oscillation (ENSO), extreme climate events and reported food shortages. Over the 120 year period between 1890 and 2009, there have been 15 widespread droughts and 13 of these were associated with El Niño events, and eight of the 12 widespread floods were associated with La Niña events. On a national scale droughts were associated with El Niño systems and wet events were associated with La Niña systems. Since the early 1900s eleven major and widespread food shortages have been reported in the highlands but they have not been associated with drought alone but also with water surplus and frost. Eight of the eleven widespread food shortages were associated with El Niño years (1997, 1987, 1982, 1972, 1965, 1941, 1932, 1911-14) and four of these were preceded by La Niña events (1996, 1971, 1964, 1910). There was evidence of anomalous frosts at lower altitudes (1450 m) and more frequent frosts at higher altitudes (> 2200 m) during clear skies in El Niño droughts that also contributed to food shortages. It is a combination of climatic extremes that causes the damage to crops that leads to a shortage of subsistence food in the highlands. The Standardised Precipitation Index provided a useful warning of success of more than 60% for El Niño droughts in 10 of the 18 locations; however the success rates of La Niña flood warnings at these locations was lower (< 60%). Using seasonal climate forecasts based on ENSO and climate integrated crop models may provide early warning for farmers, industry agencies and government to help prepare for food shortages. Strategies that can help subsistence farmers cope with extreme climate events and the use, and value of seasonal climate forecast information are discussed.