Climate change has already hit southern Africa

MANY people still think of climate change as a phenomenon that we will only face in the distant future. Perhaps, that’s partly because climate change projections about rising temperatures and extreme weather events are tied to future dates: 2030, 2050 or 2100, for instance.

But it’s important to realise that we already are experiencing climate change and have done so for some time now. Over the past century, global temperatures have increased by approximately 1°C. Sea level rise is already starting to affect certain low-lying coastal communities. The world is experiencing more frequent and intense extreme climate events.

The Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment Report: Physical Science basis, released in September 2021, contains a comprehensive – and largely grim – assessment of the state of both recorded and projected climate change globally. The IPCC is the UN body for assessing science relating to climate change – a group of expert scientists from around the world who author scientific reports on the state of the Earth’s climate and future climate change projections.

Its latest report will serve as an important reference document for the COP26 meeting in Glasgow, Scotland, from October 31 to November 12. It’s there that science is turned into policy.

Such policy is critical for the whole world – and urgent for southern Africa, which is particularly vulnerable to climatic changes. The region has already been experiencing climate changes that are more rapid and with impacts that are more severe than the global average. It also struggles with a low adaptive capacity: there’s little capital available for investment in measures to protect against future climate hazards.

There’s no avoiding the reality that southern Africa is in the throes of a climate emergency. There has been an increase in the severity and frequency of heatwave events over recent decades. Interestingly, for a few locations, there has also been an increase in the frequency of extreme cold events. While this is not a feature of climate warming, it is induced by changes in regional climate patterns, such as the number of cold fronts which move over South Africa.

Drought is defined as a significant and prolonged departure from mean rainfall totals. The most severe and best-known drought in southern Africa in recent years was the “Day Zero” crisis in Cape Town. While increasing pressure for water in the City of Cape Town played a role, a longer-term poleward displacement in the winter-rain-bearing westerlies, which bring the cold fronts to Cape Town during winter, was a significant contributor.

Southern Africa is also sensitive to El Niño induced droughts. El Niño refers to warmer than usual conditions in the Eastern Pacific, driven by a weakening of the trade winds and a resultant reduction in the up-welling of colder water to the sea surface just off South America. This was the cause of the 2015-2016 drought in the Kruger Park. Southern Africa is relatively well protected from tropical cyclones by the island of Madagascar. However, some tropical cyclones do form in the Mozambique Channel, and occasionally some tropical cyclones move across Madagascar. These storms can – and do, as was seen most recently with Tropical Cyclones Idai, Kenneth and Eloise – make landfall on Mozambique.

In recent decades, tropical cyclones in the South-west Indian Ocean have increased in intensity; the first category five tropical cyclone for the subocean basin was recorded in 1994.

There is also evidence that tropical cyclones have expanded their range polewards in recent decades, affecting a larger region of southern Africa.

In addition to the weather we experience from the changing climate itself, climate change also has an impact on biological systems. Phenology, which refers to the timing of annually recurrent biological events, is one of the most sensitive bio-indicators of climate change. In South Africa, scientists have recorded advances in the timing of apple and pear flowering in the south-western Cape and of Jacaranda flowering in the Gauteng City Region.

Warmer sea surface temperatures have also resulted in a delay in the sardine run along the Kwazulu-natal South Coast. These shifts demonstrate that climate change is having an effect on the natural environment. These shifts in timing cannot continue indefinitely. Plants and animals have thresholds beyond which the stresses of climate change will result in at least local extinction.

The picture seems hopeless, but with mitigation and adaptation strategies and policies driven through, among other processes, COP26, southern Africa can reduce the impacts of climate change on local livelihoods. It is important at this stage to invest in adaptation to reduce the impacts of climate change, and to make every effort to reduce our reliance on carbon to slow down climate change.