State of the Planet

News from the Columbia Climate School

Africa: An Air Pollution Wildcard

airplane from the NASA Atmospheric Tomography Mission
The NASA Atmospheric Tomography Mission has been flying around the world to analyze pollution chemistry in the air and oceans. And the results so far have been surprising. Photo: Roisin Commane

For the past four years, atmospheric scientists have been flying around the world with NASA on a mission to analyze pollution chemistry in the air and oceans. The NASA Atmospheric Tomography Mission or ATom, which flew its last campaign this spring, discovered unexpected levels of pollutants over the Pacific, Atlantic and Arctic oceans.

“There’s pollution everywhere in the world. The magnitude of it surprised me,” said Róisín Commane, an atmospheric scientist at Columbia’s Lamont-Doherty Earth Observatory who participated in the mission.

Analyzing the data gathered during the four-year campaign is Commane’s work for the next year or more. She joined Lamont in September as an assistant professor to start a new research group on atmospheric composition. During the fall meeting of the American Geophysical Union, she presented her ongoing analysis, highlighting one of the most surprising findings so far: the impact of African emissions on the atmospheric composition over the tropical Atlantic.

“The aim of the ATom project was to look at areas where pollution gets oxidized and dies, and to discover how much clean atmosphere is out there,” explained Commane. And while she and colleagues expected to gather a collection of well-mixed gases that would be consistent with previous research and modeling, what they found was, at times, quite unexpected.

“We’re seeing pollution in places we didn’t think we’d see it. We’re seeing chemical processes producing chemicals we never knew we should be looking for,” said Commane. Halfway between Africa and South America, investigators were astounded to see dense pollution in the middle of the ocean, so far from the source regions.

Africa produces nearly half of the world’s carbon monoxide from biomass burning. However, the research demonstrates that human-related emissions are much higher than models had indicated.

“Should we have been surprised by the magnitude? That’s what we’ll spend the next year or two asking as we analyze this data,” said Commane.

“It’s a huge continent with a lot of people. One in five people now live in Nigeria. They have a rapidly developing economy and large oil and gas industry, and they have a lot of pollution because they’re dealing with emissions from transport where they, like many countries, are using high sulfur diesel which is cheaper but much more polluting. So we should be helping these countries target what would make the biggest improvements in air quality.”

The question now, said Commane, is whether the whole continent is generating so much pollution. “We don’t know.”

Some countries are now measuring emissions on the ground, with Rwanda, Ivory Coast and Nigeria leading the way. However, there are many that do not and much is still unknown. “With ATom, we were measuring what flows out of the continent. Not what’s happening on the ground at the time.”

Finding out what’s happening on the ground, and making information available to inform regulators, is critical.

“The analysis will inform people who want to start reducing the pollution, help them decide what they should focus on first. That’s why we do all of this—to try to provide the information that will give countries the tools they need to make a difference, to help. But that’s a long way down the road.”

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Peter Kiarie
4 years ago

Hi Marie, I’m really beginning to love this place. You guys are talking air pollution, and that’s a subject i’m passionate about. I love Mother Earth, and in the footsteps of our very own Prof. Wangari Mathai (may she rest in peace), I’m always thinking about how we in Africa can help her. I’m happy that my President, Mr. Uhuru Kenyatta recently banned cutting down of trees in our forests. We had truckloads of loggers who rose every morning to fell our indigenous trees and got filthy wealthy in the process. But that’s stopped now.

Now, concerning air pollution from Africa floating above the middle of the Atlantic Ocean, I wonder how much of that came from Morocco, Ethiopia, and Egypt, 3 of the most polluted countries in Africa. In fact, Ethiopia is among the top 20 most polluted countries in the world.

I also imagine that some of that polluted air drifts toward the Indian Ocean. But how much is that pollution? Which countries in Africa are contributing to it? I’d really love to see hard numbers on that. We in Africa have been fighting and butchering one another so shameless and gluttonous politicians can clinch power and entrench themselves, their cronies, and relatives in it.

But we really should be hitting the streets for an entirely different reason: demanding a cleaner, greener Africa. I notice with much sadness that Mother Africa is drying up. The Sahara is expanding rapidly, and there seems to be no end in sight to wanton biomass burning.

If we in Africa don’t start taking big steps toward drastically reducing air pollution, we’ll soon arrive at the chilling prediction Prof. Mathai made a couple years:“…poor people will cut the last tree to cook the last meal!”

Good ol’ Columbia, I’d love for you to keep us updated on all things air pollution. It helps. I’ve shared your article on my FB and Twitter accounts so that more eye balls may see your work. Everyone needs to know that the most dangerous enemy we’re up against today is air pollution and not those who hold different political or sociocultural beliefs or values.

I’ve written an article that presents a few shocking facts about air pollution. You may want to look at it and if possible link to it. I believe it’s a resource that as many people as possible need to access.

Note: feel free to remove the link if you think it adds zero value to this discourse. Looking forward to the next article about African air pollution in particular and pollution in general.

Thank you Columbia for your unwavering dedication to education.