New research shows that West Africa’s megacities are producing mass amounts of air pollution. Not only is this having a negative impact on human health, it could alter the regional climate and cause food insecurity.
Rapidly expanding cities such as Lagos in Nigeria, Accra in Ghana and Abidjan in Ivory Coast are releasing large amounts of harmful aerosols and gaseous pollutants into the atmosphere above West Africa. As the monsoon system is particularly sensitive to aerosols, the air pollutants may be causing changes in the solar heating and clouds, which in turn could lead to changes in rainfall and temperatures.
“The story here is that climate change is happening, there’s no doubt about that,” says Professor Mat Evans of the Wolfson Atmospheric Chemistry Laboratories at the University of York and one of the authors of the study. “How that manifests itself with something like rainfall, which is what really matters, is much more complicated,” he adds.
The researchers warn that in additional to the usual concerns regarding human health, the worsening air pollution could have a dramatic impact on food security as it changes the regional climate. And those fears could extend well beyond West Africa.
Says Evans: “The environmental degradation maybe local but the implications can be regional and global. One of the potential impacts is population migration. If people have no food because the climate is changing in their region then they will move. There are knock on effects.”
The study, which was recently published in Nature Climate Change, is part of a EU-funded research project led by Professor Peter Knippertz from the Karlsruhe Institute of Technology and involving researchers from other European and African institutions.