Reducing air pollution across Africa could deliver economic returns far larger than the cost of the measures needed, research by environmental scientists Chris Malley, Kevin Hicks and Caroline Sawe finds.
In some parts of southern Africa, every dollar spent on cutting pollution could generate about 26 US dollars in economic benefits, the authors report in The Conversation, drawing on two studies that set out concrete steps for tackling air pollution and greenhouse gas emissions together.
Quelle est l’ampleur du problème de la pollution atmosphérique en Afrique ?
The scale of the health burden is set out in the “State of Global Air 2025” report, which analysed air quality and its health impacts worldwide for 2023.
It found that close to one million people died prematurely in sub-Saharan Africa that year because of exposure to air pollution, making polluted air the second major public health risk on the continent, behind malnutrition.
Older people and children are particularly affected.
The same report found that only 12% of all deaths linked to air pollution worldwide occur in sub-Saharan Africa, yet more than half of all deaths of children linked to air pollution take place there.
Most human-made air pollution in sub-Saharan Africa comes from households burning wood, charcoal and other fuels for cooking. The remainder comes from industry, power generation, transport, agriculture and waste management.
These main sources of air pollution are also the largest sources of the greenhouse gases responsible for climate change.
The first of the two studies, “Hidden assets: the economic and health case for climate and clean air action”, assesses 25 proven solutions for reducing air pollution and greenhouse gas emissions.
The measures span key economic sectors: energy and fossil fuel activities, industry, transport, agriculture and food systems, household cooking and heating, and waste management.
The 26-to-one return is calculated by comparing the cost of reducing pollution with the estimated monetary value of the damage those measures would avoid.
For comparison, the authors note that vaccinating children can generate about 16 US dollars in economic benefits for every dollar spent.
Implementing the 25 pollution-reduction measures across southern Africa would cost about 11 billion dollars by 2035, but the economic benefits could far exceed the costs incurred.
The financial gains come from savings on hospital treatment for pollution-related illness and from reduced absenteeism at work due to sickness. Lower pollution levels reduce morbidity and raise productivity.
They also cut the number of school days children miss because of conditions such as asthma.
Avoiding these costs translates into real savings for governments, and the authors argue those savings are greater still when the solutions are implemented as a coordinated package.
Quels sont les meilleurs moyens pour les pays africains de réduire la pollution atmosphérique et les émissions de gaz à effet de serre ?
The second study, “Integrated assessment of air pollution and climate change for sustainable development in Africa”, identifies 37 areas where African countries could improve air quality and health while cutting greenhouse gas emissions.
They range from cleaner cooking methods and better public transport to renewable electricity, shifting freight from road to rail, and improving the energy efficiency of factories.
The measures also recommend that farms stop burning crop residues, while cities could make waste collection more environmentally sound, turn food waste into compost or biogas, and capture greenhouse gases from landfills and wastewater treatment plants.
Two measures illustrate their impact for Africa:
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Moving households from charcoal and firewood to cleaner cooking fuels reduces both indoor and outdoor air pollution, which is responsible for a large number of child deaths in Africa.
The shift also limits short-lived climate pollutants that contribute to global warming.
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Investing in affordable, reliable public transport reduces vehicle emissions and urban smog, while lowering the cost of trips to work, school and the doctor.
Both measures are already being tested by some African countries.
In Ghana, the share of households cooking with wood and charcoal fell from 75% to 54% between 2000 and 2021, while the number of households using less polluting LPG for cooking doubled over the same period.
As a result, the death rate linked to indoor air pollution in Ghana is estimated to have fallen by about 30% over that time.
Although the absolute number of deaths from indoor air pollution rose in Ghana, the increase was far smaller than it would have been without the gradual move away from polluting fuels.
Pourquoi est-il si important de faire le lien entre la gestion de la qualité de l’air et celle du changement climatique ?
Air pollution and climate change have largely been treated as separate problems requiring separate solutions, yet the two phenomena share most of their origins.
The assessment compared the cost of each emissions-reduction measure with its expected benefits for air quality, health, climate and the economy, highlighting the overall value of each one.
Nigeria, Côte d’Ivoire and Ghana have already adopted this approach, and full implementation of their national climate plans has been shown to prevent thousands of premature deaths through air quality improvements resulting from lower emissions.
Calculating costs and benefits for each country helps development banks and other funders determine the amounts needed, the intended use of the funds and the improvements they would deliver.
Quelle doit être la prochaine étape ?
Only about 1% of international development finance is devoted to tackling air pollution, and only a fraction of that reaches African countries.
The problem lies in how development banks decide which projects to fund: their lending rules often overlook the combined benefits of reducing air pollution and fighting climate change.
Air pollution rarely has a specific funding category, and projects that address both problems at once can end up handled by two separate departments.
Acting quickly on both fronts at once generates larger economic benefits than treating the problems separately, the authors conclude.
Source: The Conversation
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