By Lily Kuo Aug 27
2015
In Lagos, smog has quickly become another aspect of city
life. In the city of more than 21 million people—known to some as “Africa’s
first city”—the majority of residents live near industrial plants, breathing in
exhaust from thousands of cars and millions of generators providing power to
the city.
Air pollution in fast-growing West African cities is
reaching dangerous levels. But the worst part, according to a new study
published by Nature magazine this week, is that we know almost nothing about
the pollutants emerging from these new urban centres and their impact on
weather systems, crops, and public health at large. There’s little monitoring
of pollution, no emissions inventories, or statistical information on things
like fuel consumption. Researchers say that they struggle to find funding to
study the issue.
“Not only is pollution in these cities killing local
residents, we found these emissions may even be altering the climate along the
coast of West Africa, leading to changes in the clouds and so potentially to
rainfall with devastating effects,” wrote the study’s co-author, Matthew Evans,
a professor atmospheric chemistry at the University of York.
In West Africa, anthropogenic emissions—those caused by
human activity—of aerosols and other gases have grown quickly and are projected
to double and possibly quadruple by 2030, especially in cities along the Guinea
Coast:
Satellite imagery from Oct. 12, 2013 shows enhanced air
pollution over coastal cities like Lagos.(“The possible role of local air
pollution in climate change in West Africa,” Nature.)
Evans and the study’s lead author, Peter Knippertz, from the
Karlsruhe Institute of Technology in Germany, worry that these pollutants will
change the West African monsoon, a sensitive atmospheric circulation system
that controls everything from wind and temperature to rainfall across huge
swathes of the region. (Scientists have previously linked aerosols to changing
rainfall patterns in Asia and the Atlantic Ocean.) Population growth in West
Africa, expected to reach 800 million by 2050, will exacerbate these effects,
they say.
(“The possible role of local air pollution in climate change
in West Africa,” Nature.)
The sources of pollution are many: car exhaust, wood
burning, garbage burning, cooking indoors with fuel stoves, the use of millions
of diesel electricity generators, petrochemical plants. “It’s not even obvious
what source to tackle first,” Evans writes.
While air pollution in India, China, and other emerging
economies has become a major area of focus for scientists and policymakers, it
has gained little traction in Africa where it’s a growing problem across the
continent.
As much as 94% of Nigeria’s population is exposed to levels
of air pollution that exceed what the World Health Organization deems as safe.
Gaborone in Botswana was the seventh-most polluted city in the world, according
to WHO data in 2013. And pollution within homes, often from fuel stoves and
diesel generators, is believed to have contributed to as many as 600,000 deaths
in Africa in 2012, the highest deaths per capita from indoor pollution of any
region in the world.
This article is published in collaboration with Quartz.
Author: Lily Kuo is a reporter, covering East Africa and
China from Nairobi.
Image: Smoke rises from the waste heap at a saw-mill at a
lagoon near the Makoko Riverine Slum in Nigeria’s commercial capital Lagos.
REUTERS/Akintunde Akinleye
