by James Thornton.

February 2024: Alex Massot – a colleague from the GEO Mountains Secretariat – and I have been kindly invited to extend our stay in Colombia by a group of mountain researchers, led by Professors Maria Elena Gutiérrez and Enrique Ángel from Universidad EIA. 

The team are keen to show us the spectacular mountain environment in which they work, and give us a first-hand impression of some of the challenges it faces and which, with support from GEO Mountains, they are working intensively to better understand.

Nevado Santa Isabel (Photo: María Elena Gutiérrez)Having piled our belongings and some scientific equipment onto the top of a large 4×4 vehicle, we descend the steep but smooth streets of the hilltop city of Manizales before embarking on an ascent of nearly 3,000 vertical metres into the mountains. 

Keeping windows open to help us acclimatise to the progressive lack of oxygen, we bump for several hours up dirt roads; first through extensive coffee plantations clinging to the clement lower hillsides, then into the rich Andean forest zone – replete with an enormous glistening waterfall – before eventually emerging in the distinctive high-elevation páramo ecosystem. 

As we enter Los Nevados National Park and arrive at our simple mountain refuge for the night, the oncoming evening and swirling mist prevents us from catching a glimpse of what lies even further above. 

The following morning dawns cold but bright, and we are now able to clearly see the features which have long drawn many visitors to the region: two spectacular volcanic peaks, atop of which sit small, brilliantly white ice caps – true rarities at such latitudes!  

A lesson from Prof. Ángel in a beautiful classroom! (Photo: María Elena Gutiérrez)As we transition from four-wheeled to two-legged transport, we learn from our colleagues that these glaciers are amongst Colombia’s last remaining tropical glaciers. They explain that while at one time the national park’s name, which translates roughly as “the snowy lands”, was extremely appropriate, the survival of these glaciers is imperilled by pronounced long-term climate warming, as well as apparent shifts in the frequency and intensity of El Niño events (the warm phase of El Niño – Southern Oscillation phenomenon), which bring hot and dry conditions to the region. For example, one of the ice caps – the Nevado Santa Isabel – is expected to disappear completely in the coming years.  

Distinctive 'páramo' vegetation (Photo: María Elena Gutiérrez)

Having now passed from the páramo into the superpáramo zone, our hike culminates at a small mountain lake which is situated at approximately 4,500 metres above sea level – a little below the rocky and icy summit of Santa Isabel. 

There, over lunch, our driver Alejandro explains how he, his colleagues, and others, who are employed in or help protect the national park, including guides and rangers, are becoming concerned that the disappearance of the snow and ice may significantly reduce its attractiveness to tourists, for whom seeing or even hiking to the glaciers is a truly memorable experience, thereby threatening their livelihoods. Half joking, Alejandro mentioned that some people are even wondering whether it would be necessary to change the park's name!

Professors Gutiérrez and Ángel then draw our attention to a wider concern: that drying of the traditionally humid peatlands of the páramos could threaten several highly specialised species of vegetation – perhaps the most emblematic being those belonging to the Espeletia genus. Given the strong interactions and feedback mechanisms between water, vegetation, soils, and carbon cycling in such systems, even small initial shifts could have major consequences for ecosystem integrity and services such as downstream water provision.   

An unobtrusive high-frequency continuous climate sensor (Photo: Alejandro Duque)

During our descent, first on foot and then by vehicle, we stop periodically and find well-concealed digital climate sensors installed by the researchers, some as long ago as 2008. At these sites, high-frequency climate measurements are downloaded, and batteries and other equipment are replaced as necessary. 

The 28 sensor locations that together comprise the Poleka Kasue Mountain Observatory span a vertical elevational gradient of almost 3,000 m. Concerningly, analysis of these long-term records has already found strong evidence that the fastest warming is occurring at higher elevations, where the remaining glaciers are located. The team has also been able to quantify temperature deviations from longer-term trends associated with El Niño. Furthermore, the detailed “on the ground” observations revealed some deficiencies in more general, so-called gridded climate data products, which must generally be relied upon in mountains in the absence of specific station measurements. This enhanced understanding of the ongoing change processes will be crucial to develop effective adaptation solutions and inform other environmental management decisions. 

Although the world’s mountain regions are extremely diverse, the vast majority are experiencing the same fundamental change as Los Nevados – generally warming temperatures, and in many cases shifting precipitation patterns. GEO Mountains works on a global basis to enhance the availability and uptake of a wide range of mountain data and information. From our work to date, we have a much better appreciation of the outstanding challenges – for example specifically where (or in which respects) station coverage and data sharing are insufficient – as well as proven solutions, such as investing in the entire “data lifecycle” (including station maintenance and human capacities). In some cases, collaboration between groups conducting monitoring for research and staff working for national monitoring agencies could also be enhanced.

The outlook for the glaciers of Los Nevados appears bleak. However, thanks to improved mountain data and the scientific research it supports, there are clear ways forward for adaptation in the face of the now largely inevitable impacts of climate change. More locally, but equally hopefully, the research team, Alejandro, and all his colleagues working in this unique setting hope that despite additional pressures, such as upward agricultural and livestock expansion, the wonders of the enlarged páramo ecosystem will be appreciated by many future visitors!

This story was developed during a workshop for the Group on Earth Observations (GEO) run by the National Geographic Storytellers' CollectiveNational Geographic Storytellers' Collective and supported by Geoscience Australia and the Australian Government.