November breaks heat records in SA — a clear reminder of what’s to come in a warming world

Map showing temperatures in each province from 23 to 27 November 2023, during the heatwave. (Image: Vox Weather)

By Julia Evans

29 Nov 2023

As parts of the country reach day 10 of a heatwave, it’s not hard to imagine that scientists are predicting that 2023 will be the hottest year in history – a clear reminder that the world is catapulting toward the dangerous 1.5°C threshold, and that extreme climate events (like heatwaves) are only going to increase in intensity and frequency as we go.

November is racking up to be the hottest month of the year in South Africa, with a number of highest maximum temperature records broken and heatwave conditions lasting 10 days across parts of the country.

Meteorologist Annette Botha, from Vox Weather, told Daily Maverick temperatures reached record-breaking highs this week – above 40°C in the Northern Cape, Limpopo, Mpumalanga, KwaZulu-Natal and the Free State, and the high 30s in Gauteng and North West.

heat records Temperatures in each province during the heatwave from 23 to 27 November 2023. (Image: Vox Weather)

Botha explained that we do get heatwaves in South Africa at this time of the year, as a result of high-pressure systems sitting over parts of the country that act like a heat dome, and as air sinks under the high pressure it heats up one degree every 100m.

“We are used to getting it at this time of the year, but having a heatwave that’s gone on for 10 days is definitely a little bit out of the ordinary and extreme,” said Botha.

This prolonged heatwave is likely a result of global warming – Botha explained that higher global temperatures mean that it’s easier for temperatures to reach the heatwave threshold – and that we have entered El Niño, which tends to have warmer and drier conditions across the country.

Francois Engelbrecht, professor of climatology and director of the Global Change Institute at Wits University, agreed, saying that “what we are looking at this year is the combined effects of ongoing global warming, with a strong El Niño event, and that has led to all these temperature records being broken across the world”.

The hottest year yet recorded

Leading up to this year’s UN Climate Change Conference (COP28), which kicks off in Dubai tomorrow (Thursday), Climate Central scientists assessed worldwide air temperatures over 12 months (1 November 2022 to 31 October 2023), and found that with an average warming of more than 1.3°C, the past 12 months were the hottest on record.

The UN Environment Programme’s latest Emission Gap Report, released this month, said that this year (until the beginning of October) 86 days were recorded with temperatures of more than 1.5°C above pre-industrial levels, and September was the hottest recorded month, with global average temperatures 1.8°C above pre-industrial levels.

Read more in Daily Maverick: New UN report (once again) warns that the world is well behind emission targets

And scientists have found that June, July, August, September and October 2023 were the hottest months since records began in the mid-1800s.

“So, you can see we are on the verge of exceeding the 1.5°C threshold of global warming for the first time,” said Engelbrecht, explaining that in terms of a single calendar year, we won’t exceed that threshold this year, but we are very close to that happening (some estimates say the late 2020s, the IPCC predicted the early 2030s).

But this is still going to be the warmest year on record. We’ve already seen exceptionally warm periods in the northern hemisphere – from Asia to Mediterranean Europe, to the southern US.

And now, as scientists predicted, these heatwave conditions have made their way to the side of the hemisphere during our summer months, because we have entered the El Niño period.

“And therefore, we can now say with certainty that 2023 will be the warmest year ever recorded by humans, with records going back to roughly 1850,” said Engelbrecht.

Yes, it really is climate change

The Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment, published in August 2021, found: “It is indisputable that human activities are causing climate change. Human influence is making extreme climate events, including heatwaves, heavy rainfall and droughts, more frequent and severe.”

Francois Engelbrecht and Coleen Vogel, from the Global Change Institute at Wits University and contributing authors to several IPCC reports, previously explained to Daily Maverick that “this [the global warming since pre-industrial levels we’re experiencing now] is likely the warmest Earth has been in 125,000 years. It is possible that during the Last Interglacial, about 125,000 years ago, the Earth has been warmer.”

Not convinced? Read in Daily Maverick: On the fence about climate change? We check the facts with scientific experts

But the difference is those periods of higher temperatures were caused by slow changes in the orbital characteristics of Earth, occurring over tens of thousands of years – the warming that has occurred since the pre-industrial era is rapid, and cannot be explained by any natural process.

Thus, they found that “global warming since the pre-industrial era is unequivocally the consequence of human activities, specifically the release of greenhouse gases such as carbon dioxide into the atmosphere, through the burning of fossil fuels”.

Risks El Niño may bring

Engelbrecht explained that the heatwaves we are seeing are typical during El Niño, because this period sees big high-pressure systems form over southern Africa, which suppress rainfall, causing more sunlight to reach the surface, warming it more than normal and lasting very long.

Vogel explained that “heatwaves and periods of extreme heat can negatively impact on people and can lead to heat dizziness, headaches and fainting”, and that “oppressive temperatures can also result in heat stroke, organ damage and unconsciousness”.

The worst-case scenario would be heat-related deaths. Heatwaves can also negatively affect livelihoods, including farming and water access and supply.

“I’m very concerned about what’s going to happen this summer in terms of heatwaves, and the impacts on our outdoor workers,” Engelbrecht said, referring to the January 2022 heatwave in the Northern Cape that killed seven farmworkers.

“A heatwave is not only a period of oppressive temperatures, it’s also a period of below-normal rainfall, and maize crops are vulnerable to heatwaves.”

Engelbrecht emphasised that extreme El Niño periods – which are naturally occuring, but whose impacts are more intense and longer lasting due to climate change – will put pressure on the agricultural sector, noting that in 2015/16, during the El Niño period, our maize crops reduced by 40% and our cattle industry, which is vulnerable to heatwaves, suffered.

El Niño can also bring the risk of drought of unprecedented duration and intensity, which also puts pressure on our water systems – less rainfall means dams will not be as full. And we are not prepared.

“Other vulnerable groups, of course, are older people living in informal settlements,” said Engelbrecht.

“This El Nino will be another important opportunity for us to learn how vulnerable we are when it comes to the impacts of drought and heat that occur in combination,” said Engelbrecht, explaining that we need to prepare for the consequences a world that has warmed by 1.5°C will bring, along with making our fair and strong contribution to mitigation (moving out of coal). DM

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South Africa

The hottest year yet recorded

Yes, it really is climate change

Risks El Niño may bring