Hot climate threat to livestock, maize crops in southern Africa

SCORCHING temperatures which might collapse southern Africa’s maize crops and Botswana’s livestock farming sector may be some of the climate change “triggers” which could influence large-scale movement of people to cities and across borders in the region.

This is according to Francois Engelbrecht, the principal researcher and research group leader for climate studies, modelling and environmental health at the Council for Scientific and Industrial Research (CSIR).

He was part of a discussion this week, organised by the Water Research Commission ( WRC), on climate-induced migration in southern Africa.

Engelbrecht’s talk focused on typical climate change induced tipping points in Africa that could lead to large migration of people.

However, he emphasised climate change was often an additional factor in systems that were already stressed. “Climate change sometimes induces a tipping point in a system,” he said.

“In the first place in Africa, we’re looking at very drastic increases in temperature. The summer of 2015/ 2016 was the warmest ever recorded. In South Africa, temperature increases of 2ºC to 3ºC have already occurred over the past century. On top of that come these big, frequent heatwave events.

“The most vulnerable systems are rain-fed subsistence farming. The maize crop is projected to be under increasing pressure from climate change.

“Some models project the total collapse of the maize crop under a six-degree warmer temperature. At best, we’re looking at massive productions in maize crop yield.

“If you’re a subsistence farmer and your crop fails two or three years in a row, you have no choice but to go to the city. That’s one big potential cause of migration. We’re not necessarily talking about people crossing country borders, but rural areas to cities and perhaps to cities in other countries with better prospects. That’s one thing we can flag.”

The second was livestock, which was already a “huge burning point” in Botswana. “This is because, already when they have big droughts, we see tens of thousands of die-offs of cattle.

“Now imagine a future world where every day is six degrees warmer than it would be. That actually means every day we exceed the critical threshold for cattle to be affected in terms of mortality.

“When the temperature exceeds 37ºC, basically, it’s life threatening for cattle. If every day in the season looks like that, you’re looking at a potential collapse of cattle farming in Botswana.”

‘We’re looking at very