What Africa's First Roadside CO2 Sensors Hope to See

Africa's first roadside vehicle emission data sensors went live in Johannesburg, the wealthiest city in South Africa, in July. The goal is to measure the tailpipe carbon dioxide (CO2) emissions from a batch of 100,000 vehicles daily. To date, no city in sub-Saharan Africa has implemented car emission-free zones like those in Paris or Amsterdam.

South Africa is the 13^th most carbon-polluting economy on earth. Raeesa Moolla, an air quality expert at the city's Wits University, reports that inhaling toxic air has resulted in 5,000 deaths, mainly from cardiovascular problems. Nationwide 429, 000 premature deaths are linked to dirty air, with coal power stations in Mpumalanga, 'the electricity belt', creating the majority of the problem.

"It's a tragedy flying under the radar", says Zwelinzima Vavi, head of the South Africa Federation of Trade Unions. 

South Africa has moved slowly to reverse the carnage of dirty air; rolling out a carbon tax – and promising to shut down old coal power plants by 2030 – "a goal that will be unrealized", says Vavi.

Fortunately, cities are taking charge of attempts to slow the spread of dirty air, with Johannesburg becoming the first in the country to deploy roadside carbon dangers. 

“It's a modest beginning, but we concluded that a carbon tax alone is of limited impact – unless we know what is the amount of fumes that cars in Johannesburg are producing daily. We want to pinpoint the most polluted highway nodes, the exact timeframes, and the vehicular type," Nomantu Nkomo, the regional health minister for Johannesburg, says of the rationale behind the roadside carbon sensors.

Dada Morero, the Johannesburg mayor, reported that 150 sensors have been placed so far. Fifty are in the low-income populated central business district of Johannesburg, and 100 are on highways around Sandton, the country’s wealthiest neighborhood. The data is remotely fed to a database that will use AI to model what's happening with car fumes – when, how, and where.

"So far, an interesting picture is forming," Morero reveals.

"In a week, the toxic carbon fumes captured in inner city is double that of the wealthier western district of Johannesburg, despite the centre of the city having 50% less the carbon sensors."

While 150 sensors have been placed across Johannesburg, there is concerns that this is not addressing the real cause of toxic air quality.

This hardly surprises Suzan Thembekwayo, a lawmaker who sits on the South African parliament's public health committee.

"First, it has taken so long, not only for South Africa, but the whole of Africa to deploy sensors and capture data on how much damage carbon fumes from cars do to citizens' lungs," she explains.

Secondly, how the carbon sensors are rolled out in Johannesburg is problematic. Most sensors are being placed in the city’s ultra-wealthy district, where cars are clean, new, or hybrid electric. Unfortunately, very few are placed in the city’s east and south, where dirty factories are placed, the population is dense, and cars are old.

“We know those who fall ill or die from dirty air are not bankers, judges, and ministers who live in Johannesburg’s posh western suburbs,” she says.

Despite these problems, this is very ‘welcome tech'; it allows for measuring how car carbon fumes are adding to the public health toll, explained Irvin Jim, secretary of the National Union of Metal Workers. Jim explains that in the past, blame for South Africa's toxic air has been placed on mines and coal power plants, where his union's members work – but very little blame has been attributed to car fumes.

“Yes – factories and power plants do produce breathable air – but what about the 11 million cars in South Africa?” Jim wonders.

On her part, Thembekwayo, the lawmaker, questions whether recording carbon emissions from 100,000 vehicles – instead of focusing tech on the coal power plants – really makes a difference in South Africa. Johannesburg has only 4 million vehicles, yet the carbon sensors deployed so far only cover two districts, akin to the size of two universities.

“We are skirting the big, difficult issue, the elephant in the room,” she says. “That is coal power plants”.

South Africa’s leaders are dragging their feet on downsizing dirty coal power plants, which are behind the illnesses and deaths from toxic air afflicting the poor residents of Johannesburg. This is due to the size and wealth of the coal lobby, Thembekwayo explained. Annually, 9,500 cases of bronchitis among children aged 6 to 12 in South Africa were directly linked to inhaling dirty air from coal power plants, a Human Rights Watch expose showed from 2017.

Silo Banxu, 29, battles chronically low energy because she was diagnosed with bronchitis. She lives near Kusile Power Station, a 4800MW coal power station, 120km east of Johannesburg. Sensors measuring carbon from cars have come too late.

“We are paying a catastrophic price,” she says, coughing repeatedly.  “Car carbon is nothing compared to the grey air here from power station fumes."