La Paz: An hour outside of La Paz, at an altitude of 5430 metres – that’s more than 3 miles above sea level – Chacaltaya (‘Cold Ridge’ in the language of the Incas) is famous among skiers for being the world’s highest lift-accessible ski slope – even if that lift is a notoriously tricky tow, powered by a car-engine dating back to the club’s inception in 1939. From around the world, adventurous skiers have flocked to Bolivia’s only ski resort to experience the thrill of flying down a mountain at an altitude higher than many planes fly.
One guide book, published in 2002, describes Chacaltaya thus:
The main slope is of intermediary difficulty but the high altitude makes it a harder level. And bear in mind that the diesel-powered tow-lift (the world’s highest ski lift) is fast and difficult to manage. The Bolivian Andean Club has a limited number of skis to rent, but not snowboards, so bring your own. Lodging is available in the club chalet, as are meals and drinks including mulled wine.
Chacaltaya is now famous among climate scientists. Ten years ago, it started to becoming increasingly difficult to ski down the mountain’s retreating glacier; scientists predicted the glacier’s eventual demise for 2015. It came sooner.
In 2008, the last ski party – a group of Bolivian firemen and military personnel – were able to make a downhill run. Last season, the glacier had melted completely.
We take a bus from downtown La Paz up and up, past houses that diminish in size and quality as we climb, turning from concrete and glass to rough adobe shacks. At some indefinable point, we leave the 2 million-strong city of La Paz (founded 1548) and enter the separate city of El Alto, founded 25 years ago and one of South America’s fastest growing cities, with already 1 million inhabitants. High, cold and poor, El Alto’s is a sprawling shanty town, which looks down on its richer, warmer neighbours rather like Rio’s faveladors do.
Climbing above the residential spread, we take a rough, rocky route that emerges onto a grassy mountainside, revealing the snowy high peaks of Illimani and Potosi, and to the far west, the vast blue of Lake Titicaca. It’s mid winter in Bolivia and normally the ground would be frozen hard, but the past three years have been so warm that farmers have been bringing sheep and llamas here to feed, and to local guide Patti Pinto’s amazement, daisies are growing.
It’s very dry here, though. Glacial run-off is used by the region’s 10 hydropower plants. The reservoir that supplies drinking water to El Alto and parts of La Paz is less than two-thirds of its size and thousands are without water. “Last year, Condoriri glacier melted, and I don’t know what we will do because Condoriri feeds the city,” says Patti. “Even Titicaca is 1 metre lower this year – scientists say that in 30 years it will no longer be one lake, but four much smaller ones.”
Patti used to take ski parties up to Chacaltaya, but has changed her service to ‘guided tours to see the beauty of the mountains’. There was a little snow this year, she tells me, but it immediately melted.
We continue up the mountain flank, passing vibrant lakes of red, blue and purple, owing to the lead, zinc and other metal content. Down below, people are mining tin, burying hand tools into great scars in the rock.
The bus climbs a winding and increasingly rocky path up the boulder-strewn slope. At one point, we have to dismount the bus so the driver can escape a particularly bad rut. The mountain sides are now slag and scree, dark rock that accelerated the glacier melt.
We pass scattered steel pyramids and yellow-painted boxes planted by astrophysicists who work at a research centre next to the ski lodge. Before particle accelerators, cosmic ray detectors like these were an important way of learning more about particles like quarks, neutrinos and muons, and understanding high-energy nuclear interactions. The air up here is much thinner than at ground level and there is far less water vapour to absorb the rays.
Our bus parks at a sorry looking wooden chalet, formerly the proud home of the Bolivian Andean Club and, until the 1990s, its Olympic ski team. Curling posters and memorabilia testify to its sporting history. We climb up the rock slope with heaving lungs, every step worsening our dizzy heads, until we reach a concrete construction holding a winch, part of the button lift that would haul skiers up here.
Out of the wind, the sun is warm and it feels unsurprising to see no snow. But this whole mountain was 50 metres thick with snow and ice 50 years ago.
We’re on the Tropic of Capricorn here; this used to be the ski resort closest to the equator. Global warming has hit tropical glaciers like Chacaltaya fastest, and the close proximity of industry and habitations in El Alto and La Paz have only enhanced the melting.
A few months ago, I spoke to tropical glaciologist Lonnie Thompson about Andean glacier melt. “We are seeing melt rates faster than anything I would have predicted 10 years ago,” he told me, describing his findings in neighbouring Peru, home of the largest tropical ice cap, which is also melting at an alarming rate.
The icy mountains have been worshipped for centuries as life-giving deities by the local Aymara tribe of Bolivians. You don’t have to be Aymaran to recognise the deadly consequences of glacier melt here.
As we head down the dry rock slope to the redundant chalet below, I am conscious that the ski slopes of Europe are approaching a similar fate, and that the water supply to Europe’s Alpine towns and villages will become similarly dry.
Wandering Gaia 
Ghostly, evocative, and terrifying. The relics of our pastimes clearly articulating the changing world around us. Thanks for an extremely informative, and necessary, post.