El Niño is essentially a climatic phenomenon characterised by anomalous warming of the ocean surface temperatures in the central and eastern equatorial Pacific. It is part of the larger El Niño-Southern Oscillation (ENSO) cycle, including its ‘cool phase’ known as La Niña. El Niño and La Niña have distinct effects on global weather patterns, thus understanding the nature of El Niño, its differences from La Niña, and its specific consequences on South Africa’s (SA) agriculture sector is crucial for managing the risks associated with this particular weather phenomenon.
El Niño and La Niña are essentially opposite phases of the ENSO cycle. During El Niño, the central and eastern equatorial Pacific experiences warmer-than-average sea surface temperatures, weakening or reversing the trade winds (wind that flows towards the equator from the north-east in the Northern Hemisphere or the south-east in the Southern Hemisphere). In contrast, La Niña is characterised by cooler-than-average sea surface temperatures, strengthening the trade winds. These variations in ocean temperatures and atmospheric circulation have far-reaching consequences for global weather patterns.
Significantly, El Niño and La Niña can affect precipitation, temperature, and storm patterns worldwide, thus impacting agriculture, water resources, and ecosystems differently. Regarding African ecosystems, in particular, the effects of El Niño on the African continent can again vary depending on the region in question. However, generally speaking, El Niño can lead to the following happening in different parts of Africa and their respective agricultural sectors:
East Africa: During El Niño, East Africa often experiences below-average rainfall, resulting in drought conditions. This can significantly affect agriculture, water resources, and food security in Kenya, Tanzania, Uganda, and Ethiopia. Droughts can lead to crop failures, livestock losses, and increased vulnerability to food shortages.
Southern Africa: El Niño can bring below-normal rainfall to parts of Southern Africa, particularly countries such as Zimbabwe, Zambia, and Malawi. This can lead to lower agricultural productivity, water scarcity, and an increased risk of wildfires. In extreme cases, prolonged droughts associated with El Niño can result in severe food shortages and humanitarian crises.
West Africa: El Niño can affect rainfall patterns in West Africa, with the potential for above-average and below-average precipitation in different subregions. The Sahel Region, for example, may experience drier conditions during El Niño events, impacting agriculture and exacerbating food insecurity. In contrast, some parts of coastal West Africa may receive increased rainfall during El Niño, leading to flooding and waterborne diseases.
EL Nino -Warmer, kouer. Goed om te weet oor ons nuwe wêreld
The Horn of Africa: El Niño can contribute to reduced rainfall in the Horn of Africa, including in countries like Somalia, Djibouti, and parts of Ethiopia and Sudan. This can exacerbate existing challenges related to drought, water scarcity, and food insecurity in the region.
Closer to home, an El Niño weather event can significantly impact SA agriculture, primarily due to the associated below-average rainfall and drought conditions. Insufficient water availability and soil moisture deficits negatively affect crop growth and development, increasing the risk of crop failures and lower yields. Maize, a staple crop in SA, is particularly vulnerable to drought. The reduced rainfall and water stress during El Niño can decrease maize production, impacting food security and affecting maize prices domestically and internationally. Other staple crops, including wheat, soybeans, and sugar cane, may also experience reduced yields.
Naturally, insufficient rainfall during El Niño affects livestock farming in SA. Limited water sources and reduced pasture growth lead to inadequate grazing, impacting livestock productivity. In turn, dairy and meat production may also decline, affecting the availability and prices of these products. In addition, El Niño can create favourable conditions for pests and diseases. Drought-stressed crops become more susceptible to infestations by pests such as armyworms and stalk borers. Consequently, reduced crop production during El Niño can lead to higher food prices in SA. Lower yields and potential crop failures may necessitate increased imports or reliance on stored reserves, impacting the general population’s greater availability and affordability of food.
However, the forecast of El Niño occurrence in the upcoming 2023/2024 summer season does not necessarily mean that SA will experience a poor agricultural season. Compared to the El Niño induced drought event from 2014 to 2016, this upcoming summer follows a rare consecutive four years of heavy rains that have improved soil moisture and natural grazing veld across the country. As a result, even if the upcoming summer rainfall is below average (generally around 500 mm), the improved soil moisture will provide a natural buffer. Nonetheless, for rainfall that does occur, it must do so during critical periods of seed germination and pollination stages of growth, for example.
Notably, the summer of 2018/2019 was marked by an El Niño event in SA. However, rainfall occurred at all the critical junctures, resulting in decent harvest volumes with commercial maize at 11.2mn tonnes, soya beans at 1.2mn tonnes and sunflower seed at 678 000 tonnes. Conversely, as with the current upcoming season, the 2018/2019 season was not preceded by a favourable four-year period of good rainfall that improved overall soil moisture. Therefore, one can logically regard SA’s current summer agricultural season as more favourable than the last El Niño period.
Overall, El Niño weather events have notable impacts on local agriculture. Drought, reduced rainfall, and water stress challenge crop production, livestock farming, and food security. It is crucial for SA to employ adaptive farming techniques, drought-resistant crop varieties, and adequate water management strategies to mitigate the potential adverse effects of El Niño. Furthermore, monitoring and early warning systems can aid farmers, policymakers, and relevant stakeholders to prepare and implement the necessary measures to safeguard domestic agriculture and ensure sustainable food production. So, whilst the SA agricultural sector may face a slightly drier 2023/2024 summer season, there is no immediate need for panic, as four years of consecutive heavy rainfall should hold us in good stead.
