Scientists monitoring extreme climate events say all indications are that Southern Africa should expect to feel the heat of another El Niño spell this summer.
This follows the release of global data showing an El Niño developing in the Pacific region, as well as recent reports of record sea surface temperatures. “Usually an El Niño results in hotter and drier weather in the summer-rainfall region of Southern Africa and can lead to local droughts,” said Dr Neville Sweijd, chair of the recently formed Extreme Climate Event Research Alliance (ECERA).
ECERA is hosting a national summit next month in Pretoria to discuss the potential impact of El Niño, an ocean-atmosphere phenomenon that influences global weather. Sweijd said the purpose of the summit was for scientists to engage civil society about recent El Niño indicators and thereby to be more prepared for possible impacts.
El Niño is part of the ENSO ocean-atmosphere system which also includes La Niña, a related phenomenon associated with higher rainfall in the summer rainfall area — of the kind witnessed in South Africa over the past few seasons. While ENSO is a naturally occurring phenomenon, there is a link with climate change, and a recent study showed the strength and frequency of this system is influenced by climate change signals, Sweijd said. “This comes on top of a recent reports that sea surface temperatures [that are important to weather systems] have been recorded at record levels which have surprised an alarmed scientists,” he said.
The ECERA summit invitation, sent out this week to a broad sweep of the scientific community, drew attention to ENSO monitoring results pointing to a “strong El Niño” in development stage. “This is the first such event [after three years of à La Niña phase] since the 2018/19 and 2015/16 events which had a serious impact on our country with significant droughts in various summer rainfall locations,” the summit notice says.
“We have called this meeting to share information with affected sectors, businesses, government departments and any stakeholders who seek to understand the basics of the climate predictions, and to consider how this may impact them. We aim to raise awareness of the pending climate anomaly and start the process of gathering information and information requirements in anticipation of its possible impact across the country.
“This will be followed up with further briefings as we learn more when we approach the summer rainfall season,” ECERA said in their invitation.
ECERA was formed specifically to establish research priorities to help South Africans prepare for extreme weather events. The move was largely a response to predictions of more extreme events linked to human-induced climate change, detailed in a report published by the Intergovernmental Panel on Climate Change (IPCC). It also follows the unprecedented scale of wildfires in California, southwestern Europe and Australia, flooding in Pakistan and Nigeria, and heatwaves in Europe, India and the US — all examples of what scientists have been predicting would results from changing climate patterns.
South Africa has its own examples of extreme climate events such as the Knysna fires, the Cape Town fires, flooding in Limpopo, KwaZulu-Natal and Eastern Cape, heatwaves and droughts in various parts of the country. These events are generally driven by a set of climatic conditions (such as cut-off low pressure systems that caused the Durban flooding in July 2022) that result in severe impacts on people and society and cause health impacts and affect food security. “Some of these events are a result of local climate and weather, but some of them are affected by global climate phenomena such as the La Nina and El Niño”, Dr Sweijd said.
Sweijd said scientists faced the challenge of disentangling the causes and impacts of extreme events, since extreme weather events do occur naturally.
“The impacts are often amplified by the fact that, as development progresses, there is infrastructure built in areas that are unsuitable or vulnerable to impact. Hence, attributing climate change causes of any one extreme weather event is difficult to do, yet very important, and so the researchers need to be able to study the patterns and trends of these incidents,” he said.
