With temperatures soaring above the average and rainfall falling below normal levels, what does El Niño mean for South Africa?
South Africans have recently experienced an unusually warm and wet winter. Still, climate experts are now sounding the alarm, warning that this summer could be one of the hottest and driest on record. The culprit? El Niño – a naturally recurring climate pattern marked by the warming of the Pacific Ocean, leading to significant shifts in weather patterns across the globe.
Understanding El Niño
The El Niño-Southern Oscillation (ENSO) is one of the most influential climate phenomena. Its ability to affect global atmospheric circulation makes it a topic of great interest for climate researchers. ENSO encompasses two main phases, El Niño and La Niña, representing the warm and cool phases of a recurring climate pattern in the tropical Pacific Ocean. Currently, experts are closely monitoring the development of a moderate-to-strong El Niño in 2023.
At a recent El Niño 2023 Summit held at the University of Pretoria, CSIR senior researcher and Alliance for Collaboration on Climate and Earth Systems Science director, Neville Sweijd, emphasised the need for early preparation in South Africa. He pointed out that global average sea surface temperatures reached unprecedented levels in May and June 2023, with record-breaking air temperatures in the northern hemisphere for June. This indicates that the El Niño expected this year might be unusually strong.
Sweijd emphasised the unpredictability of the event, saying, “Although we are certain that an El Niño is manifesting, we are uncertain about its impact at this stage. In the past, the impact was severe, and although we cannot say yet that this season will be equally affected, we must pre-empt the potential impact.”
More Frequent El Niños?
As El Niño is yet to peak, its impact on the southern hemisphere summer remains uncertain. While some parts of South Africa may experience uncertain weather patterns, others are expected to be drier than usual, a typical effect of El Niño. The models predict warmer-than-normal maximum temperatures for the season.
University of Pretoria Professor of Meteorology, Willem Landman, noted the well-established relationship between ENSO and extreme weather in South Africa. However, he emphasised that the extent of the impact can vary significantly. Historically, most previous droughts in the summer rainfall regions of the country, along with seasons marked by frequent heat waves, have been associated with El Niño events.
The South African Weather Service has shown how past ENSO events have influenced seasonal rainfall and temperature in the country. It demonstrated the significant impact of the 2015/2016 El Niño event on agricultural production, human health, and food security.
One hopeful factor is that the region has experienced good rainfall over the past few years. This could mitigate the impact of a potential drought, offering some relief to the agricultural sector and overall water resources.
Mixed Outlook for Rainfall
While El Niño is typically linked to drier conditions and above-normal temperatures, evidence for spring (September, October, and November) in South Africa suggests a dominating weather system that could bring above-normal rainfall.
According to forecasting models, the western bushveld in Limpopo, as well as parts of the Free State and North West, are expected to experience lower-than-normal rainfall during these months. In contrast, Gauteng, KwaZulu-Natal, and Mpumalanga are predicted to receive higher than normal rainfall. However, the outlook becomes less clear as we move into January, especially if El Niño intensifies into a powerful event, as some forecasters anticipate.
Preparing for the Unknown
As South Africa prepares for the potential impact of El Niño, proactive measures are crucial. While climate experts diligently monitor the situation and weather forecasting models offer valuable insights, the unpredictable nature of El Niño underscores the importance of readiness for various scenarios. This readiness can involve implementing strategies such as rainwater harvesting, efficient irrigation techniques, water-wise landscaping principles, and mulch application to protect gardens.
El Niño’s imminent arrival in South Africa heightens concerns regarding its potential to bring extreme heat and prolonged drought conditions. While the exact magnitude of its impact remains uncertain, historical data and climate models strongly indicate that vigilance and preparedness are essential to mitigate its effects on agriculture, water resources, and overall well-being. Implementing practices like rainwater harvesting and water-efficient landscaping can play a vital role in conserving precious water resources and minimising the adverse impacts of this climate phenomenon.
