Supercomputer peers into SA’s climate future — and paints a frightening picture

The Lengau supercomputer at the Council for Scientific and Industrial Research Centre for High Performance Computing in Rosebank, Cape Town, has been working on future climate models for South Africa.
In Cape Town, a modern-day oracle has peered into our future and what it saw was frightening.
The future it predicted holds killer heatwaves, storms of unprecedented power and habitat-altering droughts.
The Lengau supercomputer at the Council for Scientific and Industrial Research (CSIR) Centre for High Performance Computing in Rosebank, Cape Town, has been working on future climate models for South Africa.
What Lengau, which means cheetah in Sotho, predicted is that South Africa is likely to face four tipping point events that will cause irreversible changes to the country’s climate system.
And they could happen in the next decade or two.
The first tipping point event is a Day-Zero drought hitting Gauteng, devastating the economy of the province and causing an unprecedented humanitarian crisis.
“This is where the Vaal [Dam] is not at 95%, it is at 25%. That is a true water crisis. Because when the levels fall to below 20%, then it is really difficult to get to the water,” said Francois Engelbrecht, a professor of climatology at Wits University’s Global Change Institute.
Visit Daily Maverick’s home page for more news, analysis and investigations
“This affects businesses, industry and households. I would say there may be a risk of social unrest. And this is our single biggest climate change danger in South Africa.”
The second tipping point is the complete collapse of South Africa’s maize crops and its cattle industry. This will be brought on by a series of long-lasting droughts. Southern African farmers got a taste of this during the 2015/2016 drought during which Botswana lost 40% of its cattle.
Killer heatwaves are the third predicted tipping point, which could result in the deaths of tens of thousands.
The fourth tipping point is a weather phenomenon not yet seen in South Africa.
The warming of the Mozambique Channel is bringing the possibility of Category 4 or 5 tropical cyclones moving further south than usual and making landfall in Maputo or even Richards Bay.
Hurricane Katrina, which hit New Orleans in 2005, killing 1,800 people and causing damage amounting to $125-billion, was classified as a Category 5 tropical cyclone.
Those in the path of a Category 4 or 5 cyclone will face wind speeds of more than 200km/h, torrential rainfall of up to 1,000mm in a 24-hour period and deadly storm surges.
South ...