Heatwave warning for Africa

The latest rainfalls have not been enough to stave off drought, with many KZN farms hard hit. Picture: BONGANI MBATHA

The latest rainfalls have not been enough to stave off drought, with many KZN farms hard hit. Picture: BONGANI MBATHA

Published Nov 24, 2015

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The next three weeks could be crucial if Africa is to avoid scorching temperature increases of up to 6ºC, along with more frequent heatwaves, runaway fires and droughts.

This was the warning from a group of 11 climate researchers in the build-up to the UN’s COP21 climate talks that start in Paris next week.

They said an analysis of six computer-based climate models projected that surface temperatures in subtropical Africa could rise by between 4ºC and 6ºC by the turn of the century.

The lead author, Professor Francois Engelbrecht, of the CSIR in Pretoria, said the analysis suggested that temperatures in subtropical Africa “may plausibly rise at about 1.5 times the global rate of temperature increase”.

Paris talks

Their projections, published in a recent issue of Environmental Research Letters, are based on a low rate of greenhouse gas reductions by the more than 190 member states signed up to the UN’s framework convention on climate change.

Engelbrecht and his colleagues said the “drastic” temperature rises predicted for large parts of Africa should be at the forefront of decisions made by African policymakers at the Paris talks, which end on December 11. They also expressed concern about the strong likelihood of more frequent heatwaves in several parts of Africa.

They define a heatwave as an event in which maximum temperatures at a specific location exceed the average maximum temperature of the warmest month of the year by 5ºC, for at least three days.

Heatwaves were currently seen as rare events over Africa, with about three such events every year on average. But over the period 2071-2100, they expected there to be between 20 and 80 heatwave days over large parts of subtropical southern Africa each year.

Over the Sahara and Sahel (the zone between the Sahara Desert to the north and the Sudanian savannah to the south) regions there were likely to be between 10 and 40 heatwave days each year.

“These projections are representative of unprecedented periods of prolonged heat over Africa,” said Engelbrecht and fellow researchers from the Nasa Space Flight Centre in the US, Australia’s CSIRO, Wits University in Johannesburg, North West University in Potchefstroom and two Dutch institutions.

The rapidly rising temperature projections were likely to have “drastic impacts” on maize and cattle farmers, the environment and water security. Human health could also be affected, although the precise impacts of chronic exposure to heat were not properly understood because there had been very few academic studies focused on heat and human health.

The COP 21 meeting is the 21st annual UN meeting on climate change, underlining the slow pace of reaching a globally binding agreement to reduce greenhouse gas emissions.

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