Air pollution levels tend to rise in lockstep with a country’s economic development, which is often accompanied by an increase in the number of emissions-belching industrial enterprises. But a new study, the results of which were released earlier this month, appears to have turned this conventional wisdom on its head.

Covering the northern reaches of sub-Saharan Africa – from Senegal and Cote d’Ivoire in the west to South Sudan, Uganda and Kenya in the east – the study set out to investigate the state of air pollution in this region, said to be the most dynamic on the continent.

Conducted by researchers from the US National Aeronautics and Space Administration’s (Nasa’s) Goddard Institute for Space Studies and published in Proceedings of the National Academy of Sciences, it found that atmospheric nitrogen oxides in this region are on the decline, despite the reasonable strides it has made in terms of economic development, exemplified by Kenya’s average yearly gross domestic product (GDP) growth rate of 5.7% between 2015 and 2019. Granted, Kenya’s has been one of the better-performing economies in sub-Saharan Africa, but even the laggards did report reasonable levels of GDP growth during this five-year period.

“The traditional paradigm is that, as middle-income and low-income countries develop, you often see more emissions, and seeing another trajectory is very interesting,” Goddard Institute for Space Studies researcher and the study’s lead author, Jonathan Hickman, was quoted as telling reporters when the study’s findings were released. He added: “It’s good to see a drop happening, when you expect to see an increase in pollution.”

The researchers analysed data and satellite imagery collected by Nasa from 2005 to 2017. They put the lower quantities of atmospheric pollutants such as nitrogen dioxide – which is associated with respiratory conditions such as asthma – down to the declining incidence of bushfires started to clear land for the planting season. This is the upshot of more and more people in sub-Saharan Africa ditching agriculture in favour of other economic pursuits. The study found that, at the peak of the so-called “season of the fires”, the levels of nitrogen dioxide, which is also produced by road traffic and other fossil fuel users, decreased by about 4.5% during the period covered by the study.

It’s not all good news, though. The study’s authors explained that they expect the inverse relationship between GDP growth and atmospheric nitrogen oxide emission to start reversing when the GDP of a country reaches a certain level. “At the highest levels of this measure of GDP, air pollution levels were almost back to where they started off. What this suggests is that this decline that we are seeing is likely to slow down and could be reversed due to the increased use of fossils,” stated Hickman.

It is thus important that African countries’ efforts to curb pollution – which has become a bigger killer than HIV/Aids on the continent – should not relent. A starting point would be to intensify investment in green energy. As the African Development Bank has said, countries on this continent have the potential to deploy 11 TW of solar energy, 350 GW of hydroelectricity, 110 GW of wind-generated electricity and 15 GW of geothermal energy.

It is pleasing to note that this sort of thinking around renewable energy has struck a chord within the African Union. Speaking at a virtually held event towards the end of 2020, the continental body’s commissioner for infrastructure and energy, Amani Abou-Zeid, said: “Now is the best time to move towards a green economy. It is time to shift towards a more sustainable and emission-free transport system and industrial processes. This is the way to building a greener and better future for Africa.”

I cannot agree more.