El Niño is Coming

What to expect from Chilean and Peruvian agriculture over the coming months

by Dr. Diego Rivera

El Niño, a climate phenomenon, is marked by warmer-than-average sea surface temperatures in the Pacific Ocean. Its counterpart, La Niña occurs during cooler-than-average conditions. Both meteorological events generally develop between April and June and typically peak from October through February. These climatic episodes sustain for about nine to twelve months and tend to recur every two to seven years.

However, not every El Niño event leads to wet conditions. Furthermore, no two El Niño or La Niña episodes are alike. Their interactions with other regional climatic elements can be quite complex, largely because of the unpredictable interplay between oceanic and atmospheric processes. This level of unpredictability heightens risks to agriculture, affecting crops differently based on their respective growth stages.

El Niño’s ramifications on agriculture in Chile and Peru — two of the biggest fresh produce suppliers to the North American market — are multifaceted and varied. There are advantages, like the prospect of more rainfall suitable for long-term storage and an uptick in groundwater recharge rates.

However, there are also disadvantages, including the risk of floods, landslides, widespread crop damage and a surge in crop diseases and pests. The intensity and scope of these impacts are predominantly influenced by the geographical location. For instance, during El Niño episodes, both Chile and northern Peru generally witness a spike in precipitation levels, leading to increased runoff, paired with warmer temperatures in spring and summer.

However, an intense El Niño phenomenon doesn’t automatically equate to significant local repercussions; anomaly probabilities often diverge from the main event’s predictions. To illustrate, the 1997 and 2015 El Niño episodes were particularly robust, often termed “El Niño Godzilla,” yet Chile’s annual rainfall in 2015 was remarkably average.

With such erratic climate patterns looming, agricultural planning becomes a daunting task for farmers in these regions, regardless of whether they anticipate drier or wetter conditions. Beyond the routine agricultural tasks like planting, irrigation, harvesting and processing, managers are now squarely facing a formidable challenge: risk management.

Risk is the combination of hazards (like variations in precipitation, unexpected frosts and intense heat waves), vulnerability (measuring how well the system can withstand these hazards), and exposure (indicating the extent to which the system remains open to these threats). For instance, relocating crops to more frost-prone zones heightens exposure, whereas amplified spring rainfall intensifies the associated hazard. Therefore, farmers are advised to adapt and fine-tune their strategies to curtail vulnerabilities, especially when adjusting exposure isn’t a practical option.

Recent bouts of rainfall in Chile have hampered essential systems — spanning irrigation components such as channels, diversions, pipes and transportation structures like roads and bridges. This has stimulated a renewed interest in groundwater research. Consequently, farmers are now working diligently to rehabilitate these systems, aiming to be fully operational before the irrigation season arrives in October. This flurry of activity suggests that consumers should brace for escalating prices for staples like onions, carrots and cherries. Additionally, there might be observable shifts in supply chain dynamics and delivery schedules.

The latest predictions from Columbia University postulate that the subsequent months could usher in above-average rainfall, complemented by escalated temperatures. An increase in spring rainfalls might jeopardize orchards, especially if it aligns with critical flowering stages. Moreover, a warmer and wetter spring amplifies the probability of fungal outbreaks and pest infestations.

Thus, it’s a fitting juncture for us to reflect on our responses during past similar climate patterns, evaluate their efficacy, and start putting resilient measures and robust infrastructure in place. Perhaps no severe outcomes will materialize, or our proactive measures might counteract potential damages. But, inaction would certainly be very risky.

• Dr. Diego Rivera is a professor at Universidad del Desarrollo in Chile and the principal researcher at the Center for Water Resources for Agriculture and Mining.