Extreme thunderstorms can develop rapidly (within a few hours)

On 26 July 2016, KwaZulu-Natal’s Mercury newspaper headlines read: “KZN extreme weather causes havoc.” In Johannesburg on the same day, Eyewitness News (EWN) led with the breaking story: “Tornado hits Tembisa, several injured,” detailing how over 20 people had been hurt after a tornado hit parts of that East Rand community. And in November 2016, the SABC reported: “Heavy storm causes flash flooding havoc in Joburg.”

The weather became a trending topic both on social media and online news, with citizens sharing photos of the few moments when Mother Nature reminded us that we too are susceptible to natural disasters. Some celebrities took to social media to share their views about our apparent “crazy” weather. “A basic drainage system on the Joburg highways before focusing on e-tolls might have been a good idea. #Floods“ tweeted TV presenter, Maps Maponyane.

It was during these floods that Everite Chauke hit the headlines. Many media outlets covered the tragedy of the three-year-old toddler who went missing after the flash floods. In a TimesLIVE editorial, titled “Father tells of moment daughter was swept away in Jukskei flood”, Shadrack Chauke recounted the heart-breaking details of how his daughter had slipped out of his grip as they clung to a tree he and his family had climbed for safety, after their shack was swept away. The search went on for two weeks before her body was found.

From flash floods to tornadoes, South Africa has had its fair share of unpredictable weather recently. Mbalenhle Sibanoni asks if we should expect more of the same over the coming years.

Since then, with headline after headline, there’s been a great shift in the mindset of South Africans who’ve thought, for as long as they can remember, that these kinds of weather events only happen overseas. South African weather has, for all intents and purposes, been predictable. But with recent weather patterns shifting, evidently due to global warming, could it be that we’re no longer immune?

Senior scientist at the South African Weather Service (SAWS), Professor Hannes Rautenbach, says: “As early as 1896, global warming had been identified by the Swedish scientist Svante Arrhenius as posing a risk to global society.” In 2006, former United States vice president Al Gore’s film, An Inconvenient Truth, aimed to educate citizens about global warming and the devastating impact of climate change. Most people struggled to get their heads around the fact that such a phenomenon even existed, and certainly didn’t understand its far-reaching effects. Gore’s film is seen by many to have been the turning point at which the world woke up to the realities of climate change. Since then, life hasn’t been the same – organisations such as car manufacturers have moved towards producing cars with fewer carbon emissions and electronic vehicles, and people have begun the journey towards being “greener” and kinder to our environment.

Rautenbach explains: “Increased concentrations of greenhouse gasses in the atmosphere could lead to more heat, which is received by the sun and being emitted by Earth’s surface, to be scattered back to the lower atmosphere of the Earth, meaning that the rate of outgoing radiation to space could gradually decrease. This will disturb Earth’s radiation balance. It is the heat emitted from Earth’s surface (related to warming and temperature) that drives our weather systems (climate). This is why the term ‘global warming’ in recent years changed to the more popular term ‘climate change’.

When it comes to South Africa specifically, Rautenbach confirms that temperatures are indeed on the increase at an average of 0.14°C per decade, which is an increase that is not normal and can be associated with global warming. He says: “It is expected that this increase will get bigger in future, so that South Africa might be +3°C warmer in the 2050s and +5°C warmer in the 2080s.” Rautenbach adds that how the climate will respond to this is still an area for further research. “Whether these temperature increases are influencing our weather systems is still to be confirmed. It is too early to say with certainty whether the frequency of these weather events are already on the increase.”

Disaster management

According to a 2014 report by the Department of Environmental Affairs, titled Climate Information and Early Warning Systems for Supporting the Disaster Risk Reduction and Management Sector in South Africa under Future Climates, the world has seen an increase in the scale, frequency and extent of natural disasters.

The report states: “These disasters have increased notably over the last several years and economic losses from weather- and climate-related disasters have also increased. Southern Africa is widely recognised as one of the most vulnerable regions to climate change because of low levels of adaptive capacity, particularly among rural communities. The expected increase in weather-related disasters as a result of climate change pose significant challenges for South Africa and are expected to negatively impact infrastructure, food security, health and tourism, amongst others. The primary mechanisms for coping with climate change focus on either mitigation to reduce emissions, or on long-term adaptation. It is being increasingly argued that climate change adaptation and disaster risk management need to be integrated in order to build resilience of affected communities and to develop effective early warning systems.” In concluding sections of the report, one of its recommendations highlights how the country needs to encourage the ongoing shift from a reactive to a proactive approach when it comes to disaster management.

The overwhelming sentiment in reaction to these events has been the feeling of citizens having been caught unawares, with little or no prior warning. Rautenbach explains: “Over the past few years, the South African Weather Service (SAWS) had great success in providing early warnings of the percentage probability of extreme weather events to develop over larger areas. The difficulty has been in the exact location of where these storms are going to occur.

“Extreme thunderstorms can develop rapidly (within a few hours). It is possible, with our most advanced weather prediction models, to forecast the possibility of extreme thunderstorms to develop over larger areas up to about five days in advance (e.g. on the provincial scale) but, at the same time, it is still very difficult to forecast their exact location. Of great aid is the national weather radar network that SAWS has deployed, since radar images can provide real-time 3D images of atmospheric water/ice content. Unfortunately, such thunderstorm developments can only be forecast in the range of an hour in advance. Although not perfect, with this information the public can respond and take precaution by introducing long-term, medium-term and short-term interventions, which is far better than being caught by surprise,” he adds.

On shaky ground

As if weather changes weren’t enough to contend with, there is also the looming possibility that fault lines – lines in rock surfaces that trace geological faults – could see South Africa experiencing more earthquakes. An IOL article in March 2010 contained details of a warning by Dr Chris Hartnady, research and technical director at earth science consultancy Umvoto Africa, that SA, and particularly Durban, is at risk of an earthquake, which is difficult to imagine. Severe earthquakes happen as a result of the movement of tectonic plates – the pieces that make up the Earth’s crust. These plates are either oceanic (form the oceans) or continental (form the continents). This movement can cause earthquakes or volcanoes. In Africa, the boundary or fault line between the Nubia and Somalia plates runs from the Andrew Bain Fracture Zone in the Indian Ocean, starting underground at Port Shepstone, up through KwaZulu-Natal and Lesotho into Mozambique and all the way through north-eastern Africa. The article also goes on to state that the most severe quake the country has seen happened in 1969 in the Ceres area and measured 6.3 on the Richter scale and that, indeed, the plate boundaries in Africa are active and moving.

Last year, Durban residents took to social media to express the earth tremor they experienced on 18 August. The Council for Geoscience reported how, even though its effects were felt in Pietermaritzburg and Kokstad, the 3.1 magnitude tremor had actually originated almost 348 km away, near the Matatiele-Lesotho border. Council spokesperson Michelle Grobbelaar was quoted as saying: “It is 3.1 [magnitude] and people usually start feeling an earthquake at magnitudes of three.” She went on to advise people to “take the necessary precautions, especially if you feel your life is threatened, [avoid] going underneath something that is more solid. If you’re outdoors, just stay away from anything that can fall down, like power lines, trees and buildings.”

In an August 2014 Citizen article, titled “Earthquakes not uncommon in SA”, written after Orkney in the North West experienced a quake measuring 5.5 on the Richter scale, Grobbelaar said: “It’s difficult to pinpoint what caused the earthquake. Because this earthquake and the one in 2005 were in the same region – a mining region – it becomes difficult to find out whether it is a natural event or caused by mining.”

In terms of an overall weather outlook for the future, Rautenbach says: “The likelihood of an increase of more extreme weather events, like extreme thunderstorms, is relatively high. Although future local climate change projections do not indicate a significant change in our annual rainfall totals, the character of rainfall events might change. This might logically lead to more extreme rainfall events over shorter periods, with longer dry periods in between. Such changes might have an influence by damaging societal assets and infrastructure, which can be avoided through early risk-reduction planning and adaptation.”

An uncertain future

With the reality of a future filled with an increasing number of hazardous weather events, is it time to start building underground shelters? Rautenbach says: “South Africa is in a good position, since our Department of Environmental Affairs (DEA) is taking the risks posed by climate change seriously. Apart from mitigation interventions aimed at reducing greenhouse gas emissions (for example, through the Air Quality Act), DEA is currently in a process of implementing a National Framework for Climate Services (NFCS), which will facilitate improved communication between climatologists and society. In addition, DEA is also advancing in introducing a comprehensive sector-based Climate Change Adaptation Strategy. With these initiatives in place, society is urged to collaborate with the South African government and to respond to early warnings in creating an environment where we can all became more resilient to the risks posed by global warming, and eventually climate change.”