JOHANNESBURG, Feb 26– South Africa is at an increased risk of being directly impacted by tropical cyclones within the next 40 years, according to scientists at the University of the Witwatersrand (Wits University) here who have found that tropical storms are shifting and South Africa is already feeling the effects.
Cyclones are a system of winds rotating inwards to an area of low barometric pressure, with an anti-clockwise (northern hemisphere) or clockwise (southern hemisphere) circulation. Cyclones which hit southern Mozambique in 2007 caused heavy rain and flooding in South Africa’s Limpopo Province.
Scientist Jennifer Fitchett said that historically most cyclones hit the island of Madagascar and did not continue to Mozambique, but in the past 66 years there had been seven storms which had developed south of Madagascar and hit Mozambique head-on.
She said it looked like the start of a worrying trend. “What we see is that this warming and this shift where tropical cyclones are occurring as more polared waters start warming, we could potentially start seeing more frequent floods in South Africa such as what we saw in 2007 in Limpopo.”
In a separate study, Fitchett and others looked at different types of citrus in Iran and found that while global warming was causing the fruit trees to flower around a month earlier than 50 years ago, changes in late season frost awee not happening nearly as quickly.
She said that this could have implications for South Africa. “These kinds of increased frost risks have been occurring around the world, including the United States and Canada. South Africa, being a large citrus producer, should really start to be concerned about this because the risk is occurring globally.”
Fitchett added that this situation required a lot more observation from farmers to detect whether or not they were experiencing an increased frost risk, after flowering had occurred.