Let’s brace ourselves for worst drought
“The country is experiencing a heatwave with temperatures ranging from 36 to 41 degrees Centigrade…” How often have we seen these headlines at the bottom of our TV screens this summer? Officially, as of midMarch, the country had already experienced a total of six heatwaves. And more heatwaves were still forecast to occur before the cool season arrives. However, to many Batswana it seems that the whole of this summer, since October last year, has been one long persistent, never- ending heatwave. Now a heatwave is when we have five consecutive days when the temperature is five degrees, or more, above average. Since the average maximum daily temperature for eastern Botswana in summer is about 32 degrees, then that means that a heatwave will occur when temperatures reach 37 degrees, or more, over a five- day period.
This year, the much- loathed El Niño has reared its ugly head once again over Botswana and most of southern Africa and has indeed returned with a vengeance, as if to make up for lost time [ the last severe El Niño occurred during the 2015/ 16 summer when the Gaborone Dam dried up]. As a result, the 2023/ 24 rainy season started late, and many places did not see any rain until well into December [ normally, rains begin in November, or even in October in a good year]. Unfortunately for us, El Niño often peaks and is more intense during our summer – a time when we expect our rains. It may weaken during the following cool season, but that is little comfort to us since that is the dry season and we would not normally expect any rain at that time. El Niño is Spanish for ‘ boy child’ and refers to the birth of Christ in late December, the time when the phenomenon is at its strongest here.
The El Niño event is associated with what is happening on the other side of the world over the Pacific Ocean. Here sea surface temperatures are warmer than normal and this disrupts normal weather patterns and hence the distribution of rain bearing weather systems elsewhere on the planet, including southern Africa. And, unfortunately for us, El Niño is bad news – drought and very hot to extremely hot temperatures are the norm, as in the case of this year. During the two- month period January 20 – March 20, I only recorded 5mm of rainfall in Tonota; normally, one would expect at least 150mm during this period!
El Niño has also been intense over large parts of South Africa where temperatures have, in places, been even higher than here. In early March, temperatures were still reaching over 40C at Mussina in the Limpopo province; also, in the Northern Cape, and even in parts of the Eastern Cape where normal summer temperatures are more moderate and average about 28C. And already, some weather experts are predicting that this rainy season may go into the record books for record low rainfall.
In contrast, a La Niña event is associated with good rains and possible flooding over much of southern Africa.
To help farmers this year to mitigate the effects of the drought, the government extended the planting season for the north of the country to the end of February in the hope that late rains may enable farmers to at least harvest something. But alas, it would appear that farmers this year may not harvest anything at all, no matter when they planted. In their fields there will only be withered maize stalks swaying in the wind. The soil will be dry and the wind will raise the dry loose dust into the air causing mini tornadoes, or dust devils [ ditsuatsue]. Not exactly a scenario for ensuring food security!
In contrast, the situation has been very different in East Africa where El Niño is often associated with good rains and flooding. In November 2023, I visited Zanzibar in Tanzania and during the two weeks I was there, it rained every day except two days; on one day, it rained three times! Northern Kenya is a very dry arid area with an average annual rainfall of barely 100mm, much lower than the average for Botswana. Here, residents have raised alarm over the rising levels of water in Lake Turkana that has, not only displaced them, but has also affected their fishing activities. Floods and mudslides have also affected parts of Ethiopia and more than a million people have been affected by flooding in Ethiopia’s Somali region, a semiarid region in the east of the country. Large areas of neighbouring Somalia have also been ravaged by floods, also a semi- arid region.
[ Grahame McLeod]