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

Table 4. Possible impacts of La Niña on agriculture in Central America, the Caribbean and South America.

IV. Recommended Actions and Other Sources of Information

Next, we present recommendations aimed at mitigating the disruptive effects of La Niña on agriculture. The proposed actions vary in terms of complexity and will likely involve multiple stakeholders such as U.S. government agencies (e.g. USAID, Department of State, etc.), local government authorities, or non-governmental organizations (NGOs) familiar with regional agricultural realities. In some cases, the U.S. armed forces can play a key role by deploying critical assets when more volatile climatic conditions impact their AOs. Examples of those assets include engineer units, meteorology and topography capabilities, agricultural and agribusiness teams, U.S. Army veterinary services, etc. The recommended actions in Table 5 are again based upon a FAO report (FAO, 2016) and adjusted to the context of an intervention led by U.S. armed forces.

Table 5. Recommended actions to deal with the expected negative impacts of La Niña on agriculture.

Table 6 lists other useful information sources focused on climate and food security. All these are open-source websites and can be used by Commanders and CATs to assess risks and develop plans that respond to climate threats to food security. For instance, FAO’s Food Price Monitoring and Analysis provides historical data on prices for key food staples (i.e. corn, sorghum, and millet) in several African countries suffering from high levels of food insecurity (i.e. Ethiopia, Kenya, South Sudan, Somalia, and Uganda). As another example of the applicability of these sources, FAO Locust Watch website shows

which areas are expected to be impacted by ongoing Desert Locust swarms.

Table 6. Additional Information Sources on Climate and Food Security

V. Conclusions

This paper discusses the impacts that climate variability associated La Niña may have on agricultural production in three parts of world. It is important to note that each La Niña event will have different outcomes – they will present benefits to some agricultural producers while harming others. The effects of agricultural stress on poverty will likely be more pronounced in rural areas but will also impacts urban areas thought via higher food prices, rural-to-urban migration, etc. A better understanding of this climate phenomenon is a key success factor for food security and socio-economic stability. The U.S. armed forces can be part of the solution by participating in local efforts to mitigate the disruptive effects of La Niña. This has the added benefit of preventing 3rd party actors in countries of interest from leveraging disruptive weather events such as La Niña. This may involve the deployment of U.S. Army critical assets, the strengthening of cooperation with local authorities, leading educational programs, or supporting investments in infrastructure. Such efforts may be limited in scope and very localized, but it will inexorably take time to mobilize the needed resources. Therefore, it is important that U.S. Army leaders monitor these risks and begin to plan accordingly as soon as the meteorological community agrees on the high probability of a new La Niña phenomenon. Such a proactive stance can generate significant payoffs for the U.S. Army and could turn a negative climatic event into multiple opportunities to mitigate human and environmental suffering around the globe.


Craymer, Lucy (2020). “Weather-Upending La Niña Is Headache for Farmers World-Wide,” Wall Street Journal. Available at:

Food and Agriculture Organization of the United Nations (2016). La Niña – Update #2

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Food and Agriculture Organization of the United Nations (2020). World Food Situation.

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Golden Gate Weather Services (2020). El Niño and La Niña Years and Intensities based on Oceanic Niño Index (ONI). Available at:

International Research Institute for Climate and Society (IRI), Earth Institute, Columbia University (2020). La Niña and Rainfall. Available at:

National Oceanic and Atmospheric Administration, United States Department of Commerce (2020). El Nino Theme Page, Pacific Marine Environmental Laboratory, La Niña FAQs. Available at:

Reuters (2020). “World food price index jumps in Nov to almost 6-year high – FAO.”

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About the Authors:

Gustavo Ferreira, Ph.D. is a Senior Agricultural Economist with the U.S. Department of Agriculture and a Civil Affairs Officer serving in the 353d Civil Affairs Command as an Agricultural Officer. Prior to joining the Federal Government, he was an Assistant Professor at Virginia Tech University’s Department of Agricultural and Applied Economics and worked as Postdoctoral researcher at Louisiana State University. He holds a Ph.D. in Agricultural Economics from Louisiana State University.

Jamie Critelli is a Civil Affairs Officer serving in the 353CACOM as an Agricultural Officer. He is an independent farm business owner and has worked globally in agriculture supply chain roles on 5 continents. He graduated with honors from Cornell University, and holds a Masters of Business Administration in Supply Chain Management from Eidgenössische Technische Hochschule (ETH), Zurich.

Standard Disclaimer. The opinions, conclusions and recommendations expressed or implied above are those of the authors and do not reflect the views of any organization or any entity of the U.S. government.

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