Impacts of La Niña on Global Agriculture:What Can the U.S. Army Do About It?

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I. Introduction

The ongoing global COVID-19 pandemic and all its associated negative impacts have clearly marked 2020. To add to the list of disruptive events, we are now also seeing the rapid development and strengthening of a La Niña weather system. El Niño and La Niña are natural weather phenomena that lead to significant seasonal climate fluctuations in certain regions of the world. When these changes are more intense, they can have pervasive social and economic implications and visible impacts on the environment. For instance, severe droughts or floods caused by La Niña tend to reduce crop yields and increase food prices. This will in turn affect the livelihoods of those living in rural and urban areas, particularly those who are more vulnerable to poverty. In fact, and due to the strength of this year’s La Niña, world food prices are hitting six-year highs and experts are predicting high degrees of uncertainty in agricultural markets for 2021 (Reuters, 2020). As another illustration, abnormally dry conditions during planting season (October and November) are already impacting the ongoing soybean and corn crops in Brazil and Argentina. Because these nations are leading producers and exporters of these two commodities, this will likely result in higher prices and added market volatility throughout the rest of the value chain.

U.S. Army leadership must be aware of the impacts that these weather phenomena may have on regional stability and ongoing military operations, so they can best anticipate or react to these events. In that context, this paper seeks to inform Commanders and Civil Affairs professionals who operate in AFRICOM, SOUTHCOM, and INDOPACOM, about the impacts that a La Niña event can have on agricultural production. We present a set of weather patterns that warrant monitoring during La Niña years. Furthermore, we discuss several actions proposed by the Food and Agriculture Organization (FAO) of the United Nations that seek to minimize the negative effects impacts that La Niña may have on local food systems. These recommended actions are adapted for the military space so that Commanders and Civil Affairs Teams (CATs) may implement them in their areas of operations (AOs) with the goals of: (1) increasing local resilience to climate variability and food insecurity; and (2) precluding violent extremist organizations (VEOs) from exploiting disruptions in local food supply chains (e.g. influencing populations via distribution of food aid or recruitment of unemployed farmers who lost their crops, etc.)

II. What is La Nina?

La Niña is a recurring natural weather phenomenon characterized by cooler-than-normal waters in the Pacific Ocean that causes dry weather in some parts of the world and heavy rainfalls in others. This event occurs every few years and its conditions are felt for approximately 9-12 months, although some La Niña events have lasted for as long as two years (NOAA, 2020). Furthermore, La Niña often affects the same regions that are impacted by the other weather phenomenon, El Niño, but with the opposite climatic consequences. For instance, regions experiencing drought conditions during El Niño will likely receive above-average rainfall during La Niña (FAO, 2016). Nevertheless, it is important to note that La Niña does not always follow an El Niño (NOAA, 2020). The map below shows how La Niña tends to impact rain patterns in different parts of Africa, South America and Asia. Despite some variation from one La Niña to the next, these patterns tend to be consistent over time (International Research Institute for Climate and Society, 2020). Simply put, La Niña tends to bring heavy rains to Australia, Asia, and parts of Africa, while bringing drought to the Americas.

Figure 1. Global Distribution of Climatic Impacts of La Niña.


III. Understanding La Niña’s Impacts on Agriculture and Food Security

La Niña can have both positive and negative impacts on agriculture and food security. The main positive effect associated with La Niña is the increased likelihood of above-average rainfall. This can be particularly important for drier parts of the world because this additional rain can result in higher crop yields and improved pasture. However, U.S. Army Commanders must understand that this beneficial weather pattern will not be felt by the local population until the next crop year following this year’s harvest. On the other hand, excessive rainfall induced by La Niña, can also result in flooding of farming land and pastures. Specific negative impacts of those floods include landslides and soil erosion, the washing away of seeds, damage or loss of standing crops, increased livestock mortality, and emergence of pests (e.g., locust). Such scenarios can be particularly devasting for farmers who have been already negatively affected by El Niño in previous years (FAO, 2016).

It is imperative that Commanders and CATs have a general understanding of overall food prices in their AOs and understand how La Niña may impact them. This is a very important indicator in developing nations, where families tend to spend larger shares of their disposable income on food purchases. Hence, even slight price increases for key food staples can bring entire regions into food insecurity.

Figure 2 presents the relationship between FAO Food Price Index (shown by blue area) and the occurrence of La Niña years (represented by vertical bars). Each La Niña year is categorized and color coded according to its intensity. More specifically, the lightest color indicates a weak La Niña, whereas the intermediate and darkest tones represent moderate and strong intensities, respectively. The green bar in 2020 marks the ongoing La Niña whose intensity is yet to be determined. Prolonged La Niña phenomena, as those registered during the 1970-1976 and the 2007-2012 periods, resulted in noticeable price spikes and significant volatility in the index. There were also price increases of lesser magnitude during shorter or weaker La Niña periods (e.g. 1964-1965, 1983-1985, 1995-1996, or 2016-2018). The current La Niña is already pushing prices up for major row crops (e.g. corn and soybean) and reducing supplies of important tropical produce such as pineapples and mangos (Craymer, 2020).

Figure 2. FAO Food Price Index and La Niña Recorded Years, 1961-2020.



Commanders and CATs must also identify the vital crops and livestock species in their AO that tend to be impacted during La Niña years. While these will likely vary from region to region, Table 1 provides a list of those key commodities for Africa, South America, and Central, South, and Southeast Asia which tend to be widespread in their culture, but also reacting negatively to a La Niña event. A point to remember is that once farmers in a region commit to planting their crops, they are at the mercy of the weather all the way through to harvest. It is also important to note that even in remote parts of the world, farmers often get paid against the global commodity price for their crops, which adds to the pricing volatility in the event of regional or global crop failures. If a crop fails due to the changing climate, it may often be in the farmer’s best economic interest to try to replant it, even if the cyclical weather patterns indicate that the crop has a better than average chance of failing again. This systemic flaw leads farmers to focus strictly on “upside” economic factors while disregarding the “downside” food security factors of a 2nd crop failure.

Table 1. Key agricultural commodities per region to monitor during La Niña years.

Based on a report published by FAO (FAO, 2016), the impacts that La Niña may have on agriculture in each of those three regions are summarized on tables 2 through 4. It is suggested that Commanders and CATs operating in AFRICOM, SOUTHCOM, and INDOPACOM incorporate this information into their planning process and risk assessments. The FAO report divides Africa into two sub-regions: (1) Southern Africa; and (2) East Africa, Central Africa and Sahel regions. The South American region is broken down into two sub-regions: (1) Central America, the Caribbean and northern South America; and (2) South America. Also, the timing of the impacts of La Niña in the Asia and Pacific region varies across this very extensive geography.

Table 2. Possible impacts of La Niña on agriculture across Africa.

Table 3. Possible impacts of La Niña on agriculture in Asia