Cape Town – International climate scientists believe that man-made climate change and its effect on rainfall made the drought in the Western Cape province over the past few years about three times more likely.
Between 2015 and 2018, the province experienced below average rainfall, resulting in the worst drought since 1904.
Scientists working on the World Weather Attribution (WWA) project reported that all of the climate models used in their study showed the likelihood that droughts like the current one, while still rare, would increase with further warming.
The team looked at data for the Western Cape, which contains dams and reservoirs providing water for Cape Town and surrounding farmland.
The main factor behind the drought and the consequent water shortage was below-average rainfall rather than surface evaporation caused by high atmospheric temperatures.
Piotr Wolski, UCT researcher and co-author of the study, said: “This drought is still a rare event in the current climate, but our results suggest the risk is changing and that it’s important to improve resilience to drought.”
He added that the much-feared Day Zero had been averted for the moment, "due to the public’s adherence to water restrictions and at the cost of switching off supplies for irrigation, but this was clearly not a sustainable solution”.
Lead author Friederike Otto said: “These results are in line with our general understanding of what climate change means for semi-arid regions like southern Africa; preparing for more of the same would be wise.”
Studies cited by the WWA group say the Western Cape drought was the worst almost since the beginning of the 20th century.
The dams that supply Cape Town are entirely dependent on rainfall, making the system vulnerable to climatic variability and change, although it’s designed to cope with droughts that might occur once every 50 years on average.
Professor Mark New, the director of the African Climate and Development Initiative, said the drought taught us that climate change was not a thing of the future.
“It is happening already and impacts us today. We can no longer postpone taking precautionary and adaptive actions.”