3D model maps of disappearing tropical glaciers reveal a stark warning for the cultural future of Uganda’s Bakonzo people

Photography courtesy of Project Pressure

Project Pressure’s Klaus Thymann works with Kule Jocknus Bwabu Solomon, Muhindo Rogers of Uganda Wildlife Authority and glaciologist Heïdi Sevestre to set up precision points for photogrammetry survey.

Nestled on the border between Uganda and the Democratic Republic of Congo, the Rwenzori Mountains—a UNESCO World Heritage site—are home to some of the world’s last tropical glaciers, masses of ice that the U.N. predicts will all disappear by 2050 if current rates of warming continue.

One of Earth’s most remote and dramatic landscapes, the mountains have three main peaks, Mt. Stanley, Mt. Baker, and Mt. Speke. Mt. Stanley, with its highest peak at 5,109 meters (16,761 feet), is Africa’s third tallest mountain, with snow-capped summits and glaciers remarkably close to the equator. The ice on Rwenzori is the highest and most permanent source of the River Nile and constitutes significant water catchment areas in Uganda—relied upon by five million people, including the Bakonzo people.

The Bakonzo, who live at the foot of the mountain range, hold deep spiritual beliefs that are intricately connected to the natural landscape, particularly the snow-capped peaks. For centuries, a core belief for Bakonzo is that their gods, Kithasamba and Nyabibuya, reside in the ice of Rwenzori, a house that has been melting away. In fact, both Mt. Speke and Mt. Baker have both lost their glaciers––Mt. Baker’s loss was confirmed in 2022. Only Mt. Stanley’s glacier remains.  

The altitude data from Project Pressure’s 3D model of Mt. Stanley indicates the average melting point has reached the top of the glacier.

Knowing the glacial retreat would continue on Mt. Stanley as well, Project Pressure, a climate charity, led a groundbreaking expedition in collaboration with UNESCO and the Uganda Wildlife Authority (UWA) to the Rwenzori. The goal was to survey all three mountains to both create the first-ever 3D model of Mt. Stanley’s glaciers and install long-term monitoring equipment. The team returned with critical mapping data, scientific measurements, comparative imagery, and a stark warning about the future. 

AN EXPEDITION OF FIRSTS

Leading this expedition was Project Pressure’s director Klaus Thymann, a Danish explorer, environmental scientist, and award-winning photographer who has led expeditions since 2012 to the Rwenzori Mountains to track the demise of the tropical glaciers.

Project Pressure’s data from Mt. Stanley’s glacier reveals a loss in surface area of 29.5 percent between 2020 and 2024.

“In a world where the impact of climate change is not uniformly distributed, acquiring data on glacier recession in equatorial regions has become paramount,” says Thymann. “This is invaluable for comprehending local warming trends and their consequences to help local communities adapt.”

The 2024 expedition was designed to not only produce a 3D model of the last remaining glacier on the Stanley Plateau to visually preserve the historic record of the ice and its retreat over time, it would also install time-lapse cameras to allow local people to monitor change. Building on data from Thymann’s expeditions in 2012, 2020, 2022, and decades-long glaciological work, the 2024 mapping project would represent the most comprehensive record of the region’s glacial decline.

Key to creating the 3D photogrammetric model was a multi-source solution of geospatial technologies, including GNSS positioning, ground penetrating radar, and an unmanned aerial system.

Glaciologist Heïdi Sevestre carries Trimble Catalyst in her pack as she operates the ground penetrating radar.

Once on the mountain, the team drilled 10 orange and green vinyl survey targets into the ice at pre-determined locations. Centered on each target, they used a Trimble Catalyst DA-2 receiver, an Android smartphone running Trimble’s TerraFlex field software, and the Catalyst GNSS positioning service to collect a precise location. The small, lightweight, and easy-to-use survey technologies enabled the crew to be nimble without sacrificing accuracy. The GNSS measurements would provide the foundational data to underpin the entire 3D photogrammetry model. 

After surveying the targets, Thymann and his team conducted a drone survey over Mt. Stanley, capturing more than 850 raw images, including the geolocation points, ensuring the model’s spatial accuracy. 

In another expedition first, glaciologist Dr. Heïdi Sevestre conducted ground-penetrating radar (GPR) surveys of the the Stanley Plateau’s ice and bedrock to capture data on depth.

Klaus Thymann’s innovative combination of aerial photogrammetry and ground-penetrating radar created a data-led 3D model of Mt. Stanley.

THE BLACK AND WHITE OF GLACIAL DECLINE

With a mix of data processing solutions from Pix4D and Trimble, the team combined a drone survey from 2020 with the GNSS data, drone imagery, and GPR survey data from 2024 to create the historic, centimeter-accuracy 3D model of the glacial retreat on Mt. Stanley. Complete with the glacial depths recorded by the GPR, the model provides texture details and exact elevations for the entire mountain, the ice thickness––some depths of 50 meters were recorded––and the glacial recession over four years. 

The Project Pressure team confirmed that the glaciers on Mt. Baker and Mt. Speke have now disappeared, while the surface of the Stanley Plateau Glacier has decreased by 29.5 percent since 2020, and it’s dropped eight meters by the side. The upper regions of Mt. Stanley are still glaciated but it’s undergoing severe fragmentation, and the ice is melting at alarming rates. Thymann predicts it will likely disappear in our lifetime. 

“Seeing the surface area reduction of nearly 30 percent in four years was shocking and much more drastic than we thought,” says Thymann. “The future is bleak.”

Beyond the science, the loss is deeply cultural. For the Bakonzo people, the glaciers’ disappearance signals not just an environmental crisis, but the erosion of an irreplaceable cultural heritage.

The 2024 Project Pressure and Uganda Wildlife Authority expedition team at base in Nyakalengija.

“The Bakonzo people, who live among the mountains, are strong people who believe that the mountain is a very important aspect of their life,” says Alfred Masereka, an ecological monitoring and research ranger with the UWA. “The disappearance of the ice is bad news because it means our gods are being destroyed.”

The first-ever model not only clearly shows how much glacial ice is left on the range, it gives local teams a foundation for comparative analysis as they continue to monitor the Stanley Plateau. Project Pressure is now training and equipping local teams to collect data independently.

The Rwenzori Mountains once held glaciers on three peaks, but climate change has led to massive glacier loss. The largest glacier is the Stanley Plateau glaciers, here viewed from the side.

“The idea is that the local people, in collaboration with the UWA, collect the data,” says Thymann. That could help inform adaptation, particularly when it comes to water security and storage.

As the ice retreats, Project Pressure will continue to work with the UWA to improve glacial estimates, create mitigating strategies, and expand local capacity for ongoing research and surveyance.

“Without data, you cannot make informed decisions,” says Masereka. “But now this research will help us make decisions from an informed point of view.”