In Cape Town, a modern-day oracle peered into our days to come and what he saw was chilling. The future he predicted holds deadly heat waves, unprecedentedly powerful storms and habitat-altering droughts that will upend the country’s climate system.
The Lengau supercomputer at the Center for High Performance Computing of the Council for Scientific and Industrial Research (CSIR) in Rosebank, Cape Town, is working on future climate models for South Africa.
What Lengau, which means cheetah in Sotho, has predicted is that South Africa is likely to face four landmark events that will cause irreversible changes in the country’s climate system.
And they could happen in the next decade or two.
Tipping Point #1: Zero Day Drought
The first tipping event is a Day-Zero drought that hits Gauteng, devastating the province’s economy and causing an unprecedented humanitarian crisis.
“It is here that the Vaal [Dam] is not at 95%, it is at 25%. It is a real water crisis. Because when the levels drop below 20%, then it’s really difficult to access water,” said François Engelbrecht, professor of climatology at the Global Change Institute at Wits University.
“It affects businesses, industry and households. I would say there may be a risk of social unrest. And that’s our greatest danger from climate change in South Africa.
Tipping point 2: Long-lasting droughts
The second tipping point is the complete collapse of maize farming and the cattle industry in South Africa. This will be brought on by a series of long-lasting droughts. Southern African farmers got a taste of it during the 2015/2016 drought in which Botswana lost 40% of its livestock.
Tipping point 3: deadly heat waves
Deadly heat waves are the third predicted tipping point, which could kill tens of thousands of people.
Tipping point no. 2: Unprecedented meteorological phenomenon
The fourth tipping point is a weather phenomenon that has not yet been observed in South Africa.
The warming of the Mozambique Channel brings 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 worth $125 billion, was classified as a Category 5 tropical cyclone.
Those in the path of a Category 4 or 5 cyclone will face winds of over 200km/h, torrential rains of up to 1000mm in a 24 hour period and storm surges. murderous.
South Africa does not have a hurricane season, so its citizens and government would not be prepared for such a disaster.
Predict when they will happen
While southern African climate models see these four tipping points somewhere on the horizon, the problem is when they are likely to arrive.
“We have just launched two major research projects which, for the first time, will formally quantify the likelihood of these tipping points occurring in southern Africa over the next 10 years and the next 20 years,” Engelbrecht said.
“A project, funded by the National Research Foundation, is specifically focused on understanding the risk of a Day-Zero drought in Gauteng.”
The other project involves scientists from South Africa, Namibia, Botswana, Zambia and Germany studying heat waves and their impact on the beef industry. The project will also examine the effects of droughts on large mammals in national parks and on communities that depend on groundwater.
“So we have this group of experts and we hope to make progress in understanding these two tipping point risks in southern Africa,” says Engelbrecht.
“Because we argue that if we can go to Rand Water or the Department of Water and Sanitation, and we can give them credible published research, saying the risk is great, let’s say there is has a 30% or 50% chance that it could happen in the next 10 years, expect them to act. But if you can’t tell them exactly how big the risks are, it’s hard for them to take the right action.
A taste of things to come
Earlier this year, South Africa experienced a bit of the future Lengau warned of.
Flooding in KwaZulu-Natal in the week before Easter caused billions of rands in damage, displaced 40,000 people and claimed 448 lives.
In a warming world, more extreme weather events like the KZN floods are expected to occur.
“I think there are some very important lessons to be learned from [the KZN floods]; it shows how vulnerable we are in South Africa,” Engelbrecht said.
“We need to become more efficient in terms of our early warning systems, as well as the uptake of these warnings in communities. And if we can learn from [the KZN floods]it can help us prepare for that day when we have a category 4 or 5 hurricane moving as far south as Maputo or even Richards Bay.
Global tipping points
Countries around the world are facing the possibility of climate tipping points.
A recent study published in the journal Science concluded that multiple climate tipping points could be triggered if the global temperature rises more than 1.5°C above pre-industrial levels.
These tipping points include the collapse of the Greenland ice cap, the death of the Amazon rainforest, and the melting of permafrost.
The periods during which these tipping points occur can vary from decades to hundreds of thousands of years.
The study’s lead author, David Armstrong McKay from the Stockholm Resilience Centre, the University of Exeter and the Earth Commission, explained: “We can already see signs of destabilization in parts of the Earth’s ice sheets. West Antarctica and Greenland, in the Amazon rainforest and potentially the staggering Atlantic circulation as well.
Tipping point risks
“The world is already at risk of tipping points. As global temperatures rise, more tipping points become possible.
The Sixth Assessment Report of the Intergovernmental Panel on Climate Change stated that the risks of triggering climate tipping points become high at about 2°C above pre-industrial temperatures and very high from 2.5-4°C.
“Since I first assessed climate tipping points in 2008, the list has grown and our assessment of the risk they pose has increased significantly,” said another co-author of the paper. , Tim Lenton, director of the University’s Global Systems Institute. from Outside.
This article first appeared in Daily Maverick.
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