The combined effects of ENSO and IOD on Indonesia's coffee resilience: Differentia evidence from Arabica and Robusta production

This study analyzes the impact of El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) interactions on Indonesia's coffee production resilience from 2011 to 2024. Using secondary data from NOAA's Physical Sciences Laboratory and FAO (production statistics), the methodology involved classifying annual climate phases based on established Oceanic Nino Index (ONI) and Dipole Mode Index (DMI) thresholds. Statistical analysis showed no significant individual effect of either ENSO or IOD phases on Arabica and Robusta yields—suggesting successful mitigation through agronomic adaptations. In contrast, their combined phases demonstrated a significant effect on total production. The synergistic forcing of specific combinations, particularly El Nino with positive IOD, resulted in the most pronounced negative production anomalies. Conversely, La Nina with negative IOD conditions correlated with favorable outputs. These findings reveal that concurrent climate phenomena, rather than isolated events, present the primary risk to production. The results underscore the necessity for climate resilience strategies and early warning systems that explicitly integrate interactive ocean-atmosphere models to safeguard Indonesia's coffee sector and ensure the stability of tropical agricultural systems facing climate variability.