20 November 2023
The planet is experiencing one of the warmest years on record. The presence of El Niño and unfavourable conditions in the Indian Ocean that have a significant impact, especially on the southern hemisphere, could cause very high temperatures in South Africa from December to March, warns Johan van den Berg, an independent agricultural meteorologist.
He cautions that conditions are becoming increasingly risky and grain farmers must optimise the use of available groundwater.
Driest September since 1900 in Australia
This year, Australia experienced its driest October since 2002 with rainfall about 65% below the long-term average. Western Australia had its driest October on record. September was also the driest since 1900 for Australia as a whole.
The Australian wheat harvest is estimated to be about 35% lower than the record harvest of more than 36 million tons achieved in 2022.
“El Niño usually has an adverse effect on wheat yields in Australia with poor rainfall conditions from August to November,” says Van den Berg.
“Because the wheat-producing areas in Australia are regions where more winter and spring rains occur than in South Africa, these areas rely on rain in late winter and spring.”
Of particular interest is the correlation between spring rains, especially in the eastern production areas of Australia such as Queensland and New South Wales, and rain in mid to late summer in Southern Africa. There are already warning signs flashing for South Africa based on the conditions in Australia.
South America: El Niño and climate change bring drought
El Niño is also playing a significant role in South America this year. The northern parts of South America, mainly Brazil, are experiencing one of the severest droughts on record. The Amazon is at its lowest level in 121 years. The combination of climate change and El Niño is the most significant factor, says Van den Berg.
El Niño is known for causing drier conditions from August to March in Brazil. But the current drought is not just because of El Niño. “This illustrates the combined effect of El Niño and climate change. One source of climate change is the above-average warm sea surface temperature of almost all the northern hemisphere’s oceans.”
In summary, warning lights are flashing for a shortage of sufficient plant rains for the western production areas in South Africa in the short term, although there is still almost six weeks of planting time left.
“In the longer term, events in Australia and Brazil are particularly worrisome, with very dry conditions and poor grain harvests that could be a precursor to poorer conditions in Southern Africa as well.”
