Solving Ulaanbaatar’s pollution issues — in photos

Mongolia’s capital is among the world’s most toxic cities.

One aspirational ex-physicist is clearing the air.

Words and Photography by Dave Tacon
In Ulaanbaatar, Mongolia, winters are a matter of life and death.

The city is 1,300 metres above sea level in a valley on the Tuul River, and temperatures can plunge below −35 °C.

The average yearly temperature is around −0.8 °C, and the city nudges out Astana in Kazakhstan and Reykjavik, Iceland, to rank as the coldest capital in the world.

Around one million of Ulaanbaatar’s 1.6 million inhabitants reside in around 200,000 yurts — circular family tents, known locally as gers.

The city “was only planned for a population of 600,000” when the country was part of the Soviet bloc in the 1970s, says Unurbat Erdenemunkh, co-founder and chief science officer of local science start-up company URECA.

Now, during the winter months, huddled around furnaces inside the gers, locals burn coal, wood, tyres and even plastics for heating.

Steel chimneys spew smoke and ash, which becomes trapped in the valley.

This has resulted in one of the world’s gravest air-pollution crises, posing severe health risks.

Air-quality indices were above levels categorized as hazardous most days from December 2025 through to February, according to values recorded by the US Embassy in Ulaanbaatar.

In the deepest winter, concentrations of PM 2.5 particulates in the air reached 687 micrograms per cubic metre, 27 times higher than the World Health Organization’s recommended limit of 25 micrograms per cubic metre.

The ger itself is a structure with a history dating back at least 2,500 years, and the United Nations cultural organization UNESCO recognizes gers and the craft of making them as part of the world’s intangible cultural heritage.

When ethnic Mongol soldiers conquered medieval China and eastern Europe in the thirteenth century, they probably slept in gers similar to the ones seen today.

According to URECA, the coal burnt in household furnaces is responsible for 70–80% of the city’s smog.

Although those who burn it are contributing to climate change, many are themselves climate-displaced, having previously engaged in rural herding, a practice that one-third of Mongolians still depend on for their livelihoods.

“Catastrophic weather events in Mongolia are occurring with greater frequency,” says Erdenemunkh.

He adds that zud — a Mongolian phenomenon in which the ground freezes so completely that grazing animals starve to death — has “forced huge numbers of people to migrate to Ulaanbaatar”.

Many of the residents of the ger districts were forced to abandon their traditional lifestyle as nomadic herders, mostly owing to disastrous climatic events, including drought; others were motivated by economic reasons, such as the hope of finding better work and education opportunities.

C2S is a hybrid system, backed up by grid electricity.

A combination of heat storage, using bricks inside the ger’s heater, and energy storage using batteries, can cover up to six hours without the  grid, which is prone to outages.

Unurbat Erdenemunkh checks one of the control panels of the C2S renewable-energy system.

The lead-acid batteries installed by URECA last for three years.

Erdenemunkh, who has two young children with his wife Onon Bayasgalan, URECA’s chief sustainability officer, knows the dangers of air pollution at first hand.

Although his family lives in an apartment in an upmarket residential area, last year both their son Amirlan, now four years old, and daughter Sundari, now two, were hospitalized a total of six times with respiratory issues owing to severe air pollution.

For people who live in the ger districts, the dangers are much greater.

Carbon monoxide poisoning has killed more than 800 people in the past seven years in Ulaanbaatar.

Last winter, more than 7,000 Mongolians are estimated to have died from the effects of air pollution.

According to a 2013 study 1 , air pollution is linked to one in every ten deaths in Ulaanbaatar.

Despite this, Erdenemunkh is optimistic that his city’s dire air quality can be improved.

“Our C2S project is working,” he says.

“None of the 80 families taking part has burned coal in the past three years.

This winter, the number of families on the programme will increase to 180.”
To help gers retain the warmth of their electric heaters, URECA installs enhanced insulation.

According to a 2019 study 2 , gers lose around 25% of their heat through their roof, a self-supporting timber structure covered with woollen felt and topped with heavy-duty canvas.

Besides the heat that escapes through the walls of the ger, 10–15% of the heat is lost through the floor and 20% through its wooden door.

URECA’s thermal imaging shows that the uninsulated ger wall is at −3 °C; with insulation, the wall — known as a skirt — reaches 13.9 °C.

Likewise, the ger door is at 8.6 °C before insulation, and reaches 20.1 °C once insulation is installed.

By using a thermal camera, URECA has established that its insulation can warm sections of a ger by up to 20 °C during winter.

This is achieved through the addition of up to three extra layers of woollen felt, insulation plugs for the skirt — where the tent touches the ground — and more insulation in the domed roof and door.

The additions were developed in partnership with GerHub, a non-governmental organization in Ulaanbaatar.

This year, families with C2S systems will begin to sell excess energy back to the grid during warmer months, to offset their winter costs.

“We are hoping to generate carbon credits by the end of the first quarter of 2026,” says Erdenemunkh.

The sale of carbon credits will allow C2S’s external funders to recoup their costs, after which the families can reap the benefits.

After ten years, the operation will be handed over to households and they will be able to sell excess energy to the grid directly.

“It will really make a big difference when families see they can make money from this,” says Erdenemunkh.

“We plan to scale our C2S project up to 20,000 families in the next two years.”
Davaajargal (right) had the C2S system installed in her family ger.

Her father, Sambuu (left), followed suit.

Davaajargal creates depictions of Mongolian life.

The C2S families don’t benefit just from clean heating.

“When there’s a power blackout, they are the only ones with the lights on,” says Erdenemunkh.

“It’s this kind of story that really drives our team.”
Dave Tacon is a photojournalist in Taipei.