Addis Ababa is confronting a severe environmental challenge, as recent findings from a historic collaborative study with NASA reveal fine particulate pollution levels well above international health thresholds and black carbon concentrations significantly exceeding those in major U.S. cities.
In this interview with Capital, Associate Professor of Physics at Addis Ababa University and lead Ethiopian collaborator for NASA’s Multi-Angle Imager for Aerosols (MAIA) project, Prof. Araya Asfaw, breaks down three years of ground-level air monitoring data, the distinction between global carbon emissions and local soot, the health implications for urban residents, and the practical steps needed to build lasting scientific self-reliance. Excerpts;
Capital: The recent publication of your collaborative study with NASA has brought Addis Ababa’s air quality into the global spotlight. Could you walk us through the background of this project and why Addis Ababa was selected?
Araya Asfaw: For the past six years, we have been studying air quality in Addis Ababa in connection with NASA. Previous studies on the city’s air existed, largely driven by university students and local researchers, but they were often limited in scope and lacked long-term, permanent monitoring infrastructure.
The specific catalyst for this NASA project is the recognition that the health risks of poor air quality are inadequately mitigated globally, with developing nations bearing the heaviest burden. To address this, NASA is preparing to launch an advanced satellite dedicated to studying air quality on a global scale.
Out of 12 targeted monitoring locations worldwide—including three cities in the US, select European locations, and two African countries, Addis Ababa and a site in South Africa—our city was chosen because it represents regions facing high air quality challenges. These sites illustrate the interconnected state of global air quality. To validate the satellite’s data before launch, precise ground-level measurements are essential. We installed specialized instruments here for this purpose. The newly published results outline what Addis Ababa’s air has looked like over the past three years, and moving forward, once the satellite is active, the city’s air quality will be monitored and reported continuously.
Capital: How do these ground instruments factor into a satellite mission that operates from space?
Araya Asfaw: Before a satellite can accurately interpret data from orbit, its algorithms must be rigorously validated against actual conditions on the ground. To achieve this, a network of sophisticated monitoring instruments has been installed right here in Addis Ababa. The recently published study reflects three years of continuous data collection from these ground stations, validating our baseline metrics. Once the NASA satellite is operational in orbit—scheduled for launch no earlier than late 2027—Addis Ababa’s air quality will feed into a continuous, real-time reporting loop.
Capital: What do these baseline findings reveal about the state of Addis Ababa’s air?
Araya Asfaw: To determine whether air quality is safe or hazardous, we must measure it against internationally recognized benchmarks, specifically the guidelines established by the World Health Organization (WHO).
WHO guidelines evaluate two critical exposure windows: 24-hour concentration limits for fine particulate matter and annual cumulative exposure. According to our study, Addis Ababa currently hovers around a three-year average PM2.5 concentration of 30 micrograms per cubic meter—more than three times the annual health-based standard set by the U.S. Environmental Protection Agency.
To put that particulate density into perspective for the layperson, the physiological toll over a prolonged period can be comparable to the continuous exposure experienced by cigarette smokers. Medical professionals have extensively documented the short-term respiratory complications triggered by these particulate levels, as well as chronic long-term conditions—such as cardiovascular diseases, diabetes, and various forms of cancer—that develop after years of persistent exposure. Globally, fine particulate matter is linked to an estimated 4.9 million excess deaths per year.
The insidious nature of air pollution is that the consequences are often invisible in the short term. A young, healthy individual may feel entirely unaffected today, but as they age, their cumulative exposure drastically increases their vulnerability to these chronic illnesses. By anchoring our assessment to WHO standards, we can finally quantify precisely how vulnerable Addis Ababa’s residents are to these environmental hazards.
Capital: Are you seeing any positive policy shifts or local interventions that offer hope against this backdrop?
Araya Asfaw: There are indeed encouraging initiatives underway. Many commercial transport operators—particularly diesel-operated city buses—are gradually transitioning to electric fleets. In 2024, Ethiopia became the first country in the world to ban the import of internal-combustion-engine vehicles, while Addis Ababa has expanded bicycle infrastructure and electric-vehicle facilities. That is a commendable starting point.
We are also witnessing a significant organic shift among private vehicle owners. Because current government fiscal policy maintains low import tariffs on electric vehicles, paired with soaring conventional fuel prices and relatively inexpensive electricity, the economic incentives strongly favor electrification. We must double down on this momentum by encouraging more private motorists to make the switch. Beyond private vehicles, public sector transit agencies must accelerate the electrification of municipal bus fleets, while actively exploring other clean energy alternatives.
If we introduce broader practical measures—such as promoting natural gas-powered commercial vehicles and buses currently being adopted globally—we can drastically reduce our dependence on diesel. Lowering diesel consumption will yield an immediate, measurable improvement in urban air quality.
Another formidable challenge is domestic energy consumption, as many households still rely heavily on charcoal for cooking. Even at night when traffic decreases, we see high emissions from charcoal and other fuel combustion. We must introduce viable alternative energy sources alongside more efficient, low-emission cookstoves utilizing charcoal or sustainably harvested wood. Because our monitoring network tracks air quality continuously, any targeted municipal intervention will yield visible, verifiable data almost immediately, proving that genuine recovery is entirely within reach.
Capital: A common debate in international climate circles is that Western industrialized nations bear historical responsibility for global pollution, yet the catastrophic fallout disproportionately impacts Africa. How do you assess this asymmetry?
Araya Asfaw: To understand our environmental footprint, we have to look at the chemistry of pollutants. The primary greenhouse gas globally is carbon dioxide (CO₂). To be entirely fair, Ethiopia does not emit massive quantities of carbon dioxide relative to industrialized economies; that is not our primary domestic crisis.
The more immediate and dangerous culprit for us is black carbon—fine soot particulate matter generated by incomplete combustion. As I noted earlier, domestic charcoal burning, older imported vehicles, and heavy diesel emissions are the primary drivers of black carbon. Our study found that average black carbon concentrations in Addis Ababa were approximately four to nine times higher than levels recorded in three U.S. metropolitan areas—Los Angeles, Atlanta, and Boston.
While CO₂ lingers in the atmosphere for centuries—requiring massive, long-term reforestation efforts to offset—black carbon has a very short atmospheric lifespan, remaining for only days or weeks. Therefore, if we aggressively eliminate our local black carbon sources, we can drastically improve urban air quality in a remarkably short timeframe. Because black carbon is generated predominantly by rapidly developing economies rather than legacy industrial giants, it occupies a vital space in international climate negotiations. By cleaning our air and securing technology transfers for clean infrastructure, we can simultaneously protect public health and contribute to global climate mitigation. We must acknowledge our own local contributions, but we must also address the fact that we are bearing the disproportionate health costs of a global crisis.
Capital: When discussing these structural disparities, is the issue of climate compensation and climate justice being handled fairly for Africa?
Araya Asfaw: Compensation can be negotiated through several distinct mechanisms. For instance, through large-scale afforestation and reforestation projects, the volume of carbon dioxide absorbed by newly planted trees can be scientifically quantified, entitling nations to financial compensation proportional to verified carbon sequestration.
Simultaneously, eliminating black carbon carries an equivalent climate value. However, the most immediate and tangible dividends for Africa lie in aggressively eliminating short-lived pollutants like black carbon.
Capital: Establishing independent, long-term pollution measurement infrastructure requires robust domestic capacity. How can African nations bridge the gap between heavy reliance on foreign projects and true self-reliance?
Araya Asfaw: Achieving true self-reliance in scientific monitoring requires navigating a two-step reality. Running permanent environmental monitoring programs involves substantial, ongoing capital. Currently, we bridge this gap by leveraging established international partnerships—such as our collaboration with NASA.
Procuring scientific instruments is only the first step; those instruments must be continuously operated, and the incoming data streams must be rigorously analyzed and published. Doing this successfully requires deep collaboration with international scientific bodies to install and monitor equipment locally. Once those foundations are laid, we can systematically build domestic capacity to operate the technology independently.
We are actively moving down this path. Instruments have been deployed to Addis Ababa University, local researchers and technicians have undergone rigorous training, and equipment operation is now managed locally. Over time, air quality monitoring must be institutionalized with the same permanence as national meteorological services.
However, practical bottlenecks remain severe. Sophisticated instruments arrive at academic institutions, but maintaining them after the initial project phase presents immense challenges. Shipping a broken sensor back to a European manufacturer for repairs involves complex customs clearances, exorbitant shipping fees, and bureaucratic delays that can paralyze a project for months. Across Sub-Saharan Africa, challenges such as unstable power supplies, limited internet connectivity, and logistical constraints further complicate sustained monitoring.
Capital: Why does specialized equipment frequently break down or fall into disuse after a relatively short window?
Araya Asfaw: Equipment maintenance is much like owning an automobile: without regular, systematic servicing, mechanical systems inevitably fail. These instruments demand routine maintenance schedules, specialized calibration tools, dedicated servicing budgets, and a deep pool of trained technicians. Until our domestic technical capacity and supply chains are fully mature, reliance on foreign repair loops remains a vulnerability we must systematically engineer our way out of.
European partners transferring scientific technology to Africa must design sustainable frameworks from day one. While international support is indispensable during early development phases, our ultimate goal must be institutional self-sufficiency. In the modern world, complex technology is rarely built in isolation; it thrives on cross-border partnerships. We have established an exceptional foundation at Addis Ababa University, but transitioning to complete national self-reliance is an incremental process that takes time.
