Ulaanbaatar, Mongolia—As the sun rises over the frozen steppes, mothers and grandmothers across Mongolia emerge from their homes—white, felt-covered, round tents called gers. Hands hidden from the cold in the long sleeves of their warm deels, they clutch a ladle in one hand and an urn of milk tea in the other. Offering tsainii deej urguh, they throw a ladle-full of milk tea into the sky to honor the heavens. For many Mongolian women, the view is of blue sky and the open steppe, the horizon perhaps dotted with their family’s herd of goats and sheep. But for those who live within sight of the capital, the panorama is quite different. Before them lies a vast city, home to more than a million people, jammed into an urban sprawl of closely packed gers, Soviet-era apartments, and new high-rises. Yet in the heart of the Mongolian winter, they can see none of this. Instead, a thick, gray layer of pollution obscures the horizon. Ulaanbaatar, capital of the most sparsely populated country on the planet and renowned for its pristine countryside and nomadic herdsmen, has some of the world’s most toxic air.

The pollution is at its most intense in the winter, when over 100,000 ger stoves must work overtime to offset frigid outdoor temperatures that can dip as low as 40 degrees below zero—where Fahrenheit and Celsius overlap. In addition to generating heat, the ger stoves spew a hazardous type of pollution called particulate matter (pm) in the form of soot. Other sources, such as coal-fired power plants and vehicles, also contribute to the city’s pollution problem. When concentrations of pm in the air are elevated and the individual particles are small enough, as they are in soot, these small particles penetrate deep into the lungs, causing serious respiratory and cardiovascular problems. In the winter, portions of Ulaanbaatar can reach daily average concentrations of a particular type of pm known as pm10—particles with a diameter of 10 microns or smaller—that are 70 to 85 times the maximum daily exposure recommended by the World Health Organization (WHO).

Despite comparatively less-polluted summers when indoor heating is unnecessary, the intense winter pollution raises the annual average pm10 concentration so high that Ulaanbaatar ranks second out of over 1,000 cities in a list of the most pm10-polluted cities on the planet, according to a 2011 WHO survey—far worse than Beijing, Mexico City, or Bangkok. Only Ahwaz, Iran has a higher annual pm10 concentration.


While Ulaanbaatar represents an extreme case, it is not alone in having increasing difficulty balancing its growing need for energy with maintaining safe air. Since 2008, and for the first time in human history, we now live in a world where over half of the population resides in urban areas. The urbanization rate is highest in developing nations, where more than three-quarters of humanity live. While urban centers create the potential for efficient energy and resource disbursement, the reality is that many cities in developing countries are forced to produce more energy in inexpensive ways that compromise local air quality and their citizens’ health.

Currently, the WHO estimates that indoor and outdoor pollution causes 3.3 million premature deaths per year—substantially higher than the annual death rate from malaria and AIDS combined. The health impacts of air pollution are felt most acutely in Asia, where over the last 30 years, the population has doubled and the need for cheap energy skyrocketed. A 2002 WHO report states, that of the total urban air pollution related-deaths in 2000, nearly two-thirds of them occurred in developing countries in Asia. Of the WHO’s 10 most polluted cities, only Gaberone in Botswana is not a growing, impoverished city in Asia.

In Ulaanbaatar, the health impacts are already severe. A recent study from British Columbia’s Simon Fraser University offers a conservative estimate that 10 percent of all deaths in Ulaanbaatar are traceable to pm pollution, while a December 2011 World Bank report estimates that approximately 1,600 deaths in Ulaanbaatar, or nearly 25 percent of all the city’s deaths, can be attributed to pm every year. pm pollution has also been linked with a wide range of other negative health impacts including reproductive effects, respiratory infections, asthma irritation, impaired lung growth, cardiovascular disease, heart attacks, and strokes. The World Bank calculates that the adverse health impact of high pm levels results in nearly $500 million in losses each year—some 20 percent of Ulaanbaatar’s 2008 GDP. In short, the air pollution in Ulaanbaatar is at tragically high levels with devastating health and economic consequences to the one-third of Mongolia’s total population who live in the capital.

The health impact of particulate matter isn’t the only concern. Air pollution, especially soot from combustion sources, can affect global and regional climates far beyond their immediate source. According to some estimates, a major component of soot called black carbon is second only to carbon dioxide as the largest contributor to global warming. This material, as its name suggests, is black, and therefore can efficiently absorb and scatter incoming sunlight. Black carbon in soot can trap radiation from the sun in the Earth’s atmosphere while simultaneously dimming the surface.

Regionally, pollution in the form of pm can affect local climate by altering the types of clouds that form—indeed whether they form at all, and consequently can influence regional precipitation patterns. The increasing urbanization of Ulaanbaatar and its semi-arid climate make it especially vulnerable to small changes in precipitation. The city already struggles to provide safe water to many of those living in the ger district. Currently, there is no published research investigating how pm levels in Ulaanbaatar could be affecting precipitation and consequently threatening the delicate water supply in the region.

Push Me, Pull You

The engine of one of the world’s most rapidly developing economies, Ulaanbaatar is a prime example of an Asian city that is experiencing rapid population and economic growth while suffering severe environmental consequences due to increased energy consumption. Yet, Mongolia’s capital has its own unique set of circumstances that have created a perfect storm for the current air pollution crisis that now plagues the city.

Ulaanbaatar is spread out along the Tuul River in a valley formed by the Khentii Mountains on the north and south. Though historically the valley provided proximity to fresh water and shelter from harsh Siberian winds to the north, the city’s geography now intensifies the effects of the particles released from its pollution sources. Its valley location keeps winds from moving the pollution and dispersing it over a wider area. In the winter, the air in the valley also often experiences what is known as a temperature inversion, a common phenomenon found at higher latitudes and in mountain valleys. Essentially, temperature inversions cause pockets of cold air to lay stagnant directly above the valley, keeping polluted air trapped there, enveloping the entire city.

the nation’s growing wealth and burgeoning middle class have led to a proliferation of automobiles.

But there are many more man-made problems generated by the movement of the bulk of Mongolia’s population into this single, increasingly congested urban area. Over the past two decades, the population of the city has more than doubled. Most of this growth is attributed to an influx of nomads from the countryside. In the 1990s, the Mongolian government transitioned from a Communist authoritarian state to a parliamentary democracy, and the accompanying switch from a planned economy to a free one was not gentle. Deep recessions hit nomads with the privatization of herds and the disappearance of social safety nets that had been in place during the Communist- era. Additionally, the 2000s brought four dzuds—winter conditions that include abnormally extended periods of snowcover, high winds, and extreme cold that make it impossible for livestock to graze. Extraordinarily harsh even by Mongolian standards, the most recent dzud of Winter 2009-2010 wiped out millions of livestock, and with them, the livelihoods of hundreds of thousands of nomads.

Compounding the natural force pushing nomads into Ulaanbaatar is the pull of the city itself. In addition to being the designated seat of government, Ulaanbaatar is unquestionably the cultural, educational, and economic capital of the country. The two next most-populated cities of Erdenet and Darkhan are an order of magnitude smaller, with populations below 100,000. And perhaps most crucially, Ulaanbaatar is the business epicenter of a copper, gold, and coal mining boom that some economists project will double the 2010 GDP per capita in Mongolia by 2015.

The massive influx of former nomads into Ulaanbaatar has spawned a makeshift settlement known as the ger district. Blanketing the northern portion of the city, this vast collection of gers, wooden shacks, and fences held together by a tenuous network of dirt roads now accounts for over half of Ulaanbaatar’s population. Most of this area remains disconnected from Ulaanbaatar’s centralized heating system. The extreme cold of the Mongolian winter creates an urgent need for at least 150,000 individual heating sources in the ger district—largely individual coal and wood-burning stoves with chimneys. But wood and coal can be costly for those in the ger district, accounting for nearly half of the poorest ger families’ monthly expenses during the winter. Those who can’t afford wood or coal resort to burning rubber-coated bricks, tires, and even garbage.

While the main source of particulate pollution is from the individual stoves in the ger district, other contributing sources include heat-only-boilers that provide warmth to larger ger district buildings, such as schools and hospitals; three coal-fired power plants that provide electricity to the central part of the city; and road dust from the vast network of dirt paths that persist even within the city limits.

At the same time, at the other end of the economic spectrum, the nation’s growing wealth and burgeoning middle class have led to a proliferation of automobiles far beyond the capacity of the existing fuel infrastructure and fledgling road network to handle them safely. In just the past few years, Mongolia finally restricted the sale of leaded gasoline, notorious for its harmful neurological effects and banned many years ago by the vast majority of other countries. But vehicles that used leaded gasoline before the restriction had their catalytic converters irreparably damaged, so they now release pollutants directly into the atmosphere. About a third of all Mongolian vehicles require diesel, which produces more pm than the same mass of other fuels. Moreover, the proliferation of cars far exceeding road capacity leads to miles-long traffic jams along the capital’s single main thoroughfare, Peace Avenue. Cars, taxis, buses, and trucks—at least half of them more than ten years old—sit idling, at times for hours, belching noxious fumes and particulate matter into the already polluted atmosphere.

The high pollution has had a significant effect on the psyche of Ulaanbaatar residents. There are jokes about renaming the city “Utaanbaatar,” utaan meaning smog in Mongolian. Many express pessimism about conditions improving any time soon. “I have a headache when I walk in the polluted air, and I am thinking lately to go abroad and live there for several years just to escape from the pollution,” says Khishigbayar Tsogbadrakh, a young professional woman working in Ulaanbaatar. For those Mongolians without the option of living abroad, the pollution represents a real dilemma, choosing between a family’s health and living in the city with the nation’s best economic and educational opportunities.

the government instituted a raw coal ban in one of its nine districts as a test case.

Sereeter Lodoysamba, a professor at the National University of Mongolia who has been studying air pollution in Ulaanbaatar for several years and helped launch the first national stove-testing laboratory, raises the next logical question: “Air pollution levels exceed the WHO guidelines by a factor of 35. It is obvious that urgent intervention is needed. But how?”


One organization aggressively working to tackle the problem is the Millennium Challenge Account-Mongolia (mca-m)—a Mongolian-run agency funded by its parent organization, the Millennium Challenge Corporation, a United States foreign aid program. Since 2010, the Energy and Environment project of the mca-m has been concentrating on addressing air pollution issues by identifying and selling heavily subsidized energy efficient products, which have the added advantage of not only reducing emissions but cutting fuel costs to consumers as well.

In 2011, the $45 million project sold 40,000 energy efficient stoves, representing over a quarter of all Ulaanbaatar ger district homes. The stoves, subsidized by both the Government of Mongolia and mca-m, sell for only a fraction of their actual cost and at a price that is five to eight times cheaper than traditional ger stoves. According to mca-m Energy and Environment Project Director Dr. Sovd Mangal, the particulate matter emitted from each energy efficient ger stove should be reduced by at least 70 to 80 percent, and the stoves also require 30 to 50 percent less raw coal than traditional stoves—translating into significantly lower fuel costs for the homeowner. Mangal predicts another 30,000 to 40,000 new stoves will be sold over the rest of the winter and spring of 2012. In addition to energy-efficient stoves, mca-m has sold over 9,000 ger blankets, which provide extra insulation to the walls of the ger; 2,800 ger vestibules, which provide a buffer space between the outside and the ger living area; and nearly 100 energy efficient concrete homes.

The Mongolian government has been working with mca-m and is also instituting other measures to address the problem. The government has helped subsidize the energy efficient stoves sold by mca-m and has begun to promote what it claims are cleaner-burning, alternative stove fuels. This past winter, the government instituted a raw coal ban in one of its nine districts as a test case, offering alternative fuels such as semi-coke coal and wood chips, subsidized to 60 percent of their normal costs and comparable to the price of raw coal. If successful, the area of the ban on polluting fuels may be expanded. It is unclear how the government will gauge success. But later this year, mca-m will be testing alternative fuels with their stoves to assess how compatible the two are for generating low pm emissions. The federal government has also replaced hundreds of diesel-burning public buses and taxis with newer, more efficient and cleaner-burning models. Meanwhile, the Asian Development Bank has also funded the creation of the first stove efficiency testing laboratory in Mongolia, which could help determine what stoves are both pm and fuel efficient. The laboratory could help provide important data necessary for a national stove rating system that would inform consumers on a specific brand’s pm and fuel efficiency. Unfortunately, the source of the laboratory’s long-term funding remains uncertain.

Signs of Progress

In January 2012, in the midst of the first heating season since the mca-m energy efficient stoves have been in use, Mangal shared quantitative evidence of the project’s success: “Ulaanbaatar City Air Quality Office has been doing measurements near the ger areas and they are saying that the numbers on the measurements show, compared to the previous year, 20 percent, sometimes 25 percent reduction in pm.” It is unclear whether this comparison takes into account possible temperature differences and meteorological conditions between the two years. Still, it is a statistic that inspires optimism, considering Mangal’s estimate that 15,000 to 20,000 additional families had migrated to Ulaanbaatar by mid-winter. A more definitive verdict on the success of the project should become possible as particulate monitoring data from various air quality stations positioned around the city are analyzed in detail in the upcoming months.

No matter what the ultimate ability may be of the mca-m program to directly ease air pollution in the short-term, the project has already had long-term impact on the way residents of Ulaanbaatar view their individual ability to effect change. Mangal says when he and his team have meetings with the public, “people tell stories, like ‘On our street, everyone bought these products, and now our street is clean, with no smoke. But we look at the other streets, they are smoking. Why can’t they follow us too?’ Now they are realizing that it is possible for people to reduce the pollution. So now they are pushing others to take care of the pollution.”

He continues, “The main [long-term] advantage of this project is to show people how they can improve their living conditions by using better energy efficient products, better insulation, better combusting stoves. And of course, in the near future, maybe better, cleaner fuel. Now many people know air pollution is very bad for the health, know how to reduce the smoke pollution … and that it takes everyone’s effort to use energy efficient products.”


The mca-m program will end in Fall 2013, though there are plans for the Mongolian government to continue its work through the Clean Air Fund, a project managed by the Ministries of Environment and Energy as well as the Ulaanbaatar city government. The government also has plans to offer significant discounts for electric rates for ger district households that use electric heaters instead of stoves. While electric heaters would still consume electricity from the city’s coal-fired power plants, the net result would lower overall pm emissions. Other longer-range plans involve building and subsidizing apartments to move residents out of the ger district and into the main heating grid. All these efforts are indeed more efficient. Central power plants generate heat through combustion at much higher temperatures, which means less pm is produced. At the same time, power plants emit pollution at higher altitudes than ger chimneys and do have some pm filters. Reduced levels of pm injected higher into the atmosphere have a smaller effect on air quality. As the pm travels outside Ulaanbaatar, it will diffuse into very low concentrations as it mixes with clean air.

if successful, ulaanbaatar could serve as a role model for other cities.

National University’s Lodoysamba points out that another essential key to solving the air pollution crisis is to continually assess the progress and future direction of mitigation efforts through research like air quality monitoring, pollution source assessment, health impact analysis, and maintenance of the Asian Development Bank Stove Testing Laboratory. “Without research, huge money will be spent on nothing. We have an example that previous years’ government spent 7 billion tugriks [$5 million] on the production of briquettes, which cannot be burned well in simple stoves. … Research can [help] tell policymakers what they can do,” he says.

The World Bank’s December 2011 report on Ulaanbaatar air pollution emphasizes the integral role research should play in reducing the city’s air pollution in four parts of its 11-part recommended strategy plan. The strategy includes guidelines such as establishing target dates for reaching basic air quality standards; ensuring that abatement methods have demonstrated the ability to sufficiently lower emissions; strengthening air quality monitoring, emissions inventory, and health impact studies; and providing long-term funding for the stove testing laboratory. Following these guidelines will require more funding than is currently available for air pollution-related research. It will entail both attracting international talent and retaining Mongolia’s own experts in air pollution, atmospheric science, and public health-related fields.

One of the lowest cost implementation strategies has not received the attention it deserves: developing better ignition techniques for the existing ger stoves powered by raw coal or wood and then providing widespread education to the public about them. The hotter a fire burns in a stove, the more completely the fuel combusts, and, accordingly, the lower the particulate matter emissions are from it. This means that minimizing the time it takes to go from a cold stove to a crackling one reduces particulate matter emissions. By simply starting the fire in a different manner—for instance, further back in the stove instead of in the front or using an efficient fire-starter—and not allowing the fire to burn out as often, nearly three-quarters of all pm emissions can be eliminated from each stove. In a performance analysis of “reduced startup emissions” options, the World Bank projects a reduction of pm emissions by at least 39 percent per year over 15 years—making it not only cost-effective but also one of the few methods providing long-term savings. And most importantly, the option has one of the quickest and largest impacts on reducing negative health effects from pm. If funding were made available, determining the best ignition methods—in terms of pm emissions and practical use—for traditional ger stoves could continue in the existing national stove testing facility. This research should include testing successful methods that have already been developed for stoves in other countries. Adequate funding for research that takes advantage of other international efforts before implementation is key to successful mitigation.

A Global Laboratory

The preliminary results of the current pm mitigation methods in Ulaanbaatar are promising, but only a beginning. Long-term success will depend on continuing current pollution control efforts, improving Mongolia’s air quality research programs to monitor and direct future projects, and applying an array of mitigation strategies, including research into and widespread education on the best stove-lighting practices.

If successful, Ulaanbaatar could serve as a role model for other cities—especially in the developing world—facing similar issues. Because Ulaanbaatar is so geographically isolated from other pm emission sources and has a relatively homogenous source of pm pollution from a defined region, the effectiveness of the mitigation methods can be assessed in a way that is not always possible in other high pm regions, particularly in even more densely packed and widespread urban areas of China or India. Whatever mix of solutions Ulaanbaatar ultimately uses to beat its pollution problem, success in this invaluable urban laboratory could inspire similar strategies around the world. If Ulaanbaatar can once again become the Land of the Eternal Blue Sky, it won’t just be Mongolians who benefit.

Author notes

Christa Hasenkopf, an atmospheric scientist, is on a two-year study of particulate matter emissions in Ulaanbaatar, in collaboration with the National University of Mongolia and the University of Colorado. The research is funded by a National Science Foundation International Research Postdoctoral fellowship and a Fulbright grant.