Understanding the potential effect of the typically hotter and drier El Niño phenomenon on agriculture and food security in South Africa in the upcoming months is crucial, experts say.
Historically, the weather pattern has been associated with drier and warmer conditions over the Southern African summer rainfall region, “although this relationship is not straightforward”, said Ramontsheng Rapolaki, a researcher in agrometeorology and climate modelling at the Agricultural Research Council (ARC).
“The El Niño Southern Oscillation (Enso) is currently in an El Niño state, and according to the predictions it is expected to persist through most of the summer months. Currently, global forecasts indicate a great deal of uncertainty for the typical drier than normal conditions that South Africa experiences during an El Niño.”
El Niño and La Niña are the warm and cool phases of a recurring climate pattern across the tropical Pacific — the Enso, according to the Council for Scientific and Industrial Research. The Enso is one of the most important climate phenomena on earth because of its ability to influence global atmospheric circulation.
Above normal rainfall
Rapolaki said over the next four months, according to the South African Weather Service’s latest seasonal watch, the multi-model rainfall forecast indicates above-normal rainfall for most parts of the country during the mid- to late-spring seasons.
Above-normal rainfall is also expected in early summer (November, December and January) for the north-eastern parts. “These above-normal rainfall forecasts for the summer rainfall regions will likely have a positive impact on crop and livestock production.”
Still, below-normal rainfall is predicted over the central areas (parts of North West, Free State, Eastern Cape and Northern Cape) during the early summer season. Minimum and maximum temperatures are expected to be mostly above-normal countrywide for the forecast period.
“At this point, we need to continue monitoring how the event evolves at both weekly and monthly scales, since there is a possibility of conditions changing,” Rapolaki said.
If drier than normal conditions materialise, South Africa should be prepared. “If you look at the past El Niño’s, if the season before that one was dry, and now you’re moving to another dry season, the impact won’t be the same. Now … we’re moving from the wet season to what we can expect as El Niño-like conditions.
“For now we’re in a better position to prepare, even the fact that we’re going into early spring and early summer, we’re still expecting above average rainfall for some of the regions. It gives us some time to prepare in the long run but we don’t know what’s going to happen next year around this time … so that’s why we should prepare for that time.”
Farmers should continue monitoring advisories such as the Umlindi report, a
monthly report on drought conditions in South Africa prepared by the ARC, together with its Agriculture Drought Early Warning System and the weekly and monthly forecasts issued by the weather service.
They should stay watchful for advisories from the department of agriculture and “make necessary adjustments as required”, Rapolaki said. He urged decision-makers to advise farmers in these regions to adopt soil and water conservation practices, implement proper water harvesting and storage methods and establish effective drainage systems.
‘Very hot summer’
“What is interesting about this El Niño phenomenon is that it’s a particularly strong one,” said Janse Rabie, the head of AgriSA’s Centre of Excellence on Natural Resources.
“A lot’s been written about El Niño, the effects of that globally, but what we are seeing in the Northern Hemisphere is a record hot summer.
“And that is coinciding with the El Niño development or the El Niño Southern Oscillation over the eastern parts of the Pacific Ocean,” Rabie said. “There is a correlation and that worries us.
“They normally last for anything between six and 18 months and normally we expect hotter, drier conditions. If what is happening in the Northern Hemisphere bears out, then we’re in for a very hot summer in the Southern Hemisphere and with us in particular.”
The difference between the current period and the extreme drought of 2015-16 was that “that we’ve had about four years of very good rainfalls all over the country. The soil moisture content for agriculture, for crop producing areas of the country, is good”.
“Our concern is mainly heat and heat stress and what that would do for the various commodities, but we do think that we’re in a good position at least for the six to 18 month period with regard to higher temperatures, coupled with lower rainfall.”
In late summer, “that’s where we expect really high temperatures and low rainfall and where we hope that our built up resources – the soil moisture content and dam levels – carry us through”, Rabie said.
Load-shedding plus El Nino spells trouble
Load-shedding is placing severe additional strain on the agricultural sector, Rabie said. “We saw that in the last season — and we had a good rainfall season — that load-shedding had enormous implications for irrigation farming in particular and definite negative and adverse effects.
“Should it be that we have to experience the same thing that we did in the past summer months for the irrigation periods in the harvest cycle, then we do need to worry,” he said. “Particularly if we go into a longer El Niño cycle, 18 months or longer, coupled with a drought, which is not unforeseeable, then we’re in for a much more unstable harvest season and agricultural financial year in particular.”
Load-shedding is detrimental for irrigation farming in particular, Rabie said.
Johan Malherbe, a senior researcher at the ARC’s Natural Resources and Engineering division, agreed. “The big thing with load-shedding is that when you have a warmer and drier period, then you don’t get slack from the climate system because you don’t get your shower instead of having to irrigate and it’s hot and there’s more evaporation so you need to irrigate more often.
“Then under such conditions, if you have load-shedding at schedule six, you can … really see that impacting on the yields you get. If we do see the potential negative impacts of the El Niño, in terms of lower rainfall and high temperatures this summer, and that coincides with very high stages of load-shedding, it will have a further negative effect on the irrigation farming sector.”
On the potential for food inflation, Malherbe said an oversupply of maize in the summer can lower food prices. “We had that during the previous summer, an oversupply, so our maize was relatively cheap as we moved towards the late summer.
“But now if you have a summer where you don’t produce sufficient maize to export and you might have to import, and also taking into account that usually if you have a strong El Niño and the drought occurs over South Africa, usually it is also affecting our neighbouring countries and then we export white maize to these countries.”
Then, there is a larger export demand regionally “so the import demand from other countries around us … if we have a drought, which usually it’s a regional drought in El Niño, so then also there’s a bigger demand for our maize.”
If South Africa doesn’t produce as much as it does during a wet year, “that can also in terms of keeping the food inside the country, it can also support the price very strongly and that can have a food inflation effect”.
He noted how in 2015-16 and even the summer thereafter because of the knock-on effect, “we had much higher maize prices than the international price because of this effect so higher maize prices than the parity”.
El Niño occurs on average every two to seven years and episodes typically last nine to 12 months, the World Meteorological Organisation said. “It is a naturally occurring climate pattern associated with warming of the ocean surface temperatures in the central and eastern tropical Pacific Ocean. But it takes place in the context of a climate changed by human activities.”
It said 2016 is the warmest year on record because of the “double whammy” of a very powerful El Niño event and human-induced warming from greenhouse gases. “The effect on global temperatures usually plays out in the year after its development and so will likely be most apparent in 2024.”