This was the last field day of the Bern leg of the sabbatical, and the one that we’ve been talking about the most since.

From Kandersteg we took the gondola to get up to the typical tourist location (restaurant and panorama) to get past the huge crowds and cut 30 minutes off our hike in just 5. From there we hiked up to the Blüemlisalphütte, a Swiss Alpine Club hut at about 2,800 metres. Our watches put it at 5.5 miles, 4,253 feet of climbing, and a high point of 9,539 feet, four and a quarter hours of walking. We each carried three litres of water, more than double what this walk would normally need, because the streams and troughs we'd usually refill from half way up were dry. A few days earlier, on the Grindelwald hike, a farmer had told us the helicopters we kept hearing were flying water up to the livestock for exactly that reason. The extra weight was hard going on a steep pitch where parts of the trail had washed out or collapsed; in a few places we clipped slings and carabiners to fixed steel cables to keep from sliding down the scree.

The hut that night was full, hikers from across Europe, some of them walking the Via Alpina long-distance route over consecutive weeks. I stepped inside for a minute and came back out to the deck to find Ginny with a beer bigger than her head. We could both feel the altitude; my watch showed a resting heart rate of 110 instead of the usual 60. We played cards with a friendly Swiss banker whose family was in Singapore, on his first-ever night in a mountain hut. At dinner a group of Germans at one end of the table kept to themselves, while a young Finnish couple and a Polish traveler at our end were glad to talk and even send us some of the photos they took of their glacier hikes. There is a well-known Polo Hofer song, "Alperose," built around a night up at the Blüemlisalp; it’s an ear worm so once I thought about the song it took a few days to get it out of my head.

We had come to photograph the Blüemlisalp glacier against images we have from 2017. Even in eight years the difference is plain in the frames. We're not going to put a single percentage on this one glacier, because the data is less readily available and the pictures are straight forward. Across Switzerland the pace has picked up. In 2023, ninety percent of the glaciers measured for length retreated by between 4 and 80 metres, about 23 percent faster than the 2010-2020 average (GLAMOS), and the country lost close to a tenth of its total glacier volume in the two hot summers of 2022 and 2023 alone. So, not only are glaciers melting faster than ever, the speed they are melting is increasing further still.

The next morning we started down at 7 am, and around 11 am, as we came back toward the Oeschinensee (Lake Oeschinen), we slowed down to scoot past a farmer and his goats on the narrow trail when we heard a rumble. On the earlier days we'd seen propeller planes and that water helicopter, so our first thought was another aircraft, and we looked to the sky. But the sound kept going, more like thunder, and to borrow Nan Shepherd's line from The Living Mountain, there was "nothing in all the sky but light." Then, across the lake and up the far slope, a cloud of dust went up, and boulders began coming down the face from the ice near the top, picking up more rock as they fell, until they crashed to a stop uncomfortably close to the water, where people were kayaking and swimming. All the hikers and visitors froze to watch, but the goats kept eating and the farmer kept arguing with them and whooping loudly with his staff in the air trying to move them along.

We learned afterward that this is a known and growing danger here, not a freak event, as evidenced by the farmer’s lack of reaction. Above the Oeschinensee stands a rock formation called the Spitze Stei, holding an estimated 15 to 20 million cubic metres of unstable rock. Since 2018 it has been watched around the clock with GPS, radar, and drones, because thawing permafrost (long-frozen ground and rock that acts like glue in the mountains) is breaking down; sensors have measured it moving up to 70 centimetres in a single day (GEOTEST; Associated Press). A large enough collapse could reach Kandersteg, a village of 1,300 people, as a debris flow, which is why the community has built barriers and drawn up evacuation plans. Officials have compared the risk to the collapse that buried the village of Blatten in the Lötschental in May 2025.

We saw more rockfall later on the trip, in the Engadin near Morteratsch and above the Aletsch. Near the end of our trip as we were wrapping up our hikes in the alps France's busiest route up Mont Blanc was closed due to dangerous rockfall: on 11 August 2026, Saint-Gervais shut the Tête Rousse and Goûter refuges over heat-driven rockfall in the Grand Couloir, where two climbers had died earlier that month, and the mayor told 32 people who pushed on anyway that they would have to pay for their own helicopter down (municipal order ARR2026_014; Saint-Gervais).

We had one day for this on our compressed schedule, so we photographed the Blüemlisalp glacier, spent the night, and came down. The rockfall was obviously not on the shot list and unfortunately we were not quick enough to capture it.

Two of the glaciers we visited this summer are ones you can now ride to, and both are being actively managed to slow their melt. That combination, easy access plus engineering, makes them a different kind of subject from the valley tongues we'd been repeating from old photographs.

We warmed up on 13 July with a lower hike toward the Lauenensee (Lauenen lake), mostly to get used to the camera before the real standpoints. Two days later, on 15 July, we went up to Glacier 3000, the ski area on the Tsanfleuron and Scex Rouge glaciers above Les Diablerets, now reachable by cable car. The first thing you notice up top is huge strips of fabric covering big piles of last winter's snow. The white geotextile fleece, a synthetic cloth that reflects sunlight and insulates the ice beneath, reduces summer melt in the covered strips by somewhere between 50 and 70 percent (Huss and others). We were told the covers here were a newer wood-pulp type rather than the usual plastic; the standard synthetic fleece sheds microplastics into the meltwater, which is why biodegradable versions are now being trialed on Alpine ice.

The tourism around it is hard to miss. On the train up from Bern we'd passed private jets parked on the airstrips near Gstaad. We stayed nearby in a friend's parents' apartment. Up on the glacier the day was crowded, right up until we were setting out across the glacier itself. Around noon the staff called off all glacier hiking for safety, and a huge fast-moving storm arrived almost as soon as we were on the cable car down. The hail was the size of peanuts, small but enough to sting, and we spotted a cracked windshield in the parking lot at the bottom, validating our choice to ride down instead of hike. We got our shots of the plateau from above, but never made it out onto the ice or to its edge due to the weather.

On 22 July we went up to the Wildstrubel, to the Plaine Morte (Dead Plain) plateau above Crans-Montana, using a cable car to get quickly up away from the town and then hiking on foot across the more interesting terrain. It reads nothing like a valley glacier. Instead of a frozen river it's a flat white field, more like a frozen lake, and we photographed it against images we have from 2019.

The Plaine Morte is also a warning about the fate of glaciers in the alps. The plateau has thinned so much that its surface has dropped below the ridge that used to send its meltwater south toward the Rhône; now the water drains north instead, toward the village of Lenk (SwissEduc; GEOTEST). An ice-dammed lake on its edge, the Lac des Faverges, has burst almost every summer since 2011. In July 2018 it emptied in about a day and flooded parts of Lenk, ten kilometres downstream, damaging buildings and forcing evacuations (Copernicus, The Cryosphere). Since 2019 the community has kept it in check with a channel cut into the glacier ice to drain the lake on purpose before it can let go on its own.

So these are the glaciers you don't have to earn on foot, and they are the ones wrapped in fabric and plumbed with drainage channels. On our compressed schedule we took the lift at both for time and safety since we didn’t have the time to wait for a weather window to fully hike / climb each on foot. The convenience and the management are part of the same story: this is what it now takes to keep a glacier that a resort, or a village, cannot afford to lose.

On 17 July we spent the day at the Alpine Museum of Switzerland (Alpines Museum der Schweiz) in Bern. The exhibits at the time weren't especially close to our subject, but the museum's postcard collection was, and some of those cards go back to the 1890s. They have turned out to be our best source of repeatable "then" images so far. In most of them the glacier isn't really the point. It sits in the background behind sunbathers, or over the shoulders of men playing lawn games; the postcards served scenery for a summer holiday to tempt tourists into a holiday in the alps. Nobody was photographing the ice on purpose, which is exactly what makes the cards useful now. We bought physical copies, and their older origins solves the reproduction rights challenge.

The next day, 18 July, we went to Grindelwald to shoot the "now" for a few of them. We repeated views of the Lower Grindelwald Glacier and its Ischmeer (Ice Sea) tributary from two standpoints: down in the town, and higher up at Berghaus Bäregg, a mountain inn reached on foot.

I (Dan) also had a second "then" to measure against. Eleven years ago I spent a season here guiding Swiss teenagers from around the world, hiking, rock climbing, camping, and mountain biking for the Organization of the Swiss abroad. The town had tourists then, but nothing like today. If you wanted to get up near the glacier you mostly hiked, because there weren't the cable cars there are now. The high slopes still held visible snow through the summer. The restaurants and bars were smaller, and the people working in them were Swiss, speaking Bärndütsch (Bernese dialect).

Standing in the same streets this July, the layout was familiar but almost everything else had changed. The town is bigger, more crowded, and much more expensive. The staff is international now, and the default language in a café is English. Walking the main street, I recognized none of the businesses except the big grocery chains, and a lot more of the frontage than I remembered is given over to shops selling tourist souvenirs.

The glacier had moved the other way. Between 2013 and 2017 alone, the Lower Grindelwald Glacier retreated 1,308 metres, roughly 1.3 kilometres in four years (GLAMOS). As it pulled back it left a lake behind, which threatened the valley with sudden outburst floods, so a tunnel was built to drain it. The tongue (frontmost tip of a glacier) that a visitor could once walk toward now sits well up the mountain and out of sight from most of the town. The glacier’s retreat happens up the hill and around the corner of the mountain while the shops and gondolas multiply at eye level.

The drought this summer made itself felt on the walk up to Bäregg. We carried all our own water, because the stream-fed cow troughs we'd normally expect to refill at along the way were dry. A farmer we passed told us the helicopters we kept hearing were flying water up to the high pastures, since the troughs the animals drink from had run empty. It was the first clear sign of how hard the summer had dried out the range, and not the last we would see.

We had one day here on our compressed twelve-week schedule, so we shot the standpoints we could reach on foot and moved on. There are more of the Bern cards to match on later trips.

In the Library of Congress there is a colour print of the Rhône Glacier from around 1900. The Hôtel Belvédère sits on its hairpin bend on the Furka road, and the glacier fills the valley just below it, a broad tongue of ice close enough that guests could walk out to it after breakfast. The people who bought that print as a souvenir were not documenting anything; they likely just wanted a pretty picture of a holiday in the Alps. Now that picture serves as a measurement.

Stand at that same bend today and the ice is gone from the frame. The Rhône has pulled back roughly 1,300 metres up its valley over the last century, and lost around 60 percent of its volume since 1850 (Swiss glacier monitoring). The hotel closed years ago. The tongue (frontmost tip of a glacier) that once filled the postcard now sits far up the slope, and in summer the Swiss partly wrapped the glacier white blankets to slow the melt.

Almost none of the great historic glacier photographs were taken as science. They were postcards, tourist snapshots at the ice grotto, mountaineering trophies, the occasional survey plate. A century later they have become the most honest long-term visual record of the ice we have, and repeat photography is the tool that turns them back into data.

The Alps hold one of the longest photographic glacier records anywhere. The Rhône was easy to reach and drew tourists from the 1870s. The Mer de Glace above Chamonix and the glaciers of Mont Blanc were sketched, painted, and then photographed from the middle of the 18th century onward. Those scattered images have since been pulled together into real archives. The Glacier Photograph Collection alone holds something like 25,000 images, some dating to the mid-1800s (NSIDC). This is not a fringe method, either. The US Geological Survey has been re-photographing Glacier National Park since 1997, matching modern frames to originals shot between 1887 and 1943, and the resulting pairs became some of the most widely shared climate images in the country (USGS).

The history and the exercise we are undergoing on this sabbatical reveal an additional manmade twist on capturing and sharing these glaciers - copyright law. The photographs we can freely use are the old ones. In the United States that now means roughly anything published before 1931, and across the Alps copyright usually runs until seventy years after the photographer dies. That leaves a gap right where it hurts, across much of the twentieth century, including the decades when the melt truly began to accelerate. To use those images, an independent researcher, a teacher, or a curious student often has to track down the rights holder, ask permission, sometimes pay, and sometimes just be told no (if you can get a hold of the owner at all). It is a strange barrier to build around a shared record of a shared loss, and a big reason we wanted our archive to live in the public domain from the start.

A historic image is only useful if you can pin down three things: when it was taken, exactly what it shows, and where the camera sat (Euro-Climhist, University of Bern). That last one is the real hunt. Vantage points do not stay put. A spot that was open pasture in 1900 is now forest. A hotel terrace becomes a car park. And sometimes the original photographer was standing on the glacier itself, which means you need a drone to suspend the camera in the air. A classic photo of Robert F. Kennedy taken on the Rhone glacier in 1938 with the massif towering in the background is just such a photo, unrepeatable without a drone to suspend the camera 30+ feet in the air. I'd love to share it here, but as mentioned using this photo requires express permission to reproduce online... so I'll just share the link while I wait to hear back from the JFK Library on permission to reshare it here. (https://jfk.blogs.archives.gov/2017/09/08/the-rhone-glacier-evidential-value-of-a-kennedy-family-photograph/)

A couple of the images on our shortlist show why the numbers land harder as pictures. The Rhône is the obvious one. That Belvédère viewpoint gives a clean before and after, more than a century apart, from almost the same patch of road.

The Mer de Glace gives you something even more literal. Every year a crew carves an ice cave into the glacier for visitors, and every year the staircase down to it has to grow longer, because the ice keeps dropping away beneath it. It reached 580 steps by the early 2020s. Here is what those steps are measuring: beneath the Montenvers station the ice was about 250 metres thick around 1915, and at cave level in 2023 it was roughly 30 (Luc Moreau, Train du Montenvers). Each new flight is an accidental ruler, bolted on one summer at a time. The glacier has also given up close to two kilometres of its length since 1850.

So over the next few weeks, that is the work. Pull the best historic frames we can find for "then," work out where the camera stood, then go stand there and shoot "now." Some of those old vantage points will have vanished, and we will have to get as close as the changed ground allows. That gap, between where they stood and where we can, is part of the record too.

PS. It has been really fun practicing German, French, and Italian (and even using a little bit of Spanish) while traveling around Switzerland on this project.

In the fall of 2024, Switzerland and Italy agreed to move their shared border. The reason was not political. The glacier that had defined the frontier high on the Matterhorn massif for more than a century had melted enough to shift the watershed beneath it, so the old line no longer matched the ice. The two countries sat down and redrew the map.

We tend to picture climate change as something measured in centuries (or at least decades) and global averages, abstract enough to argue about or to think “well someone will figure that out.” Glaciers remove that abstraction. They keep a plain physical ledger of every warm summer and thin winter, and right now the ledger is grim.

Since 1976, the world's glaciers, setting aside the Greenland and Antarctic ice sheets, have lost more than 9,000 billion metric tonnes of ice. That is roughly a quarter to a third of all the sea level rise measured, a contribution that now rivals that of rapidly melting Greenland (World Glacier Monitoring Service). About 40 percent of that loss has come in the last decade alone. For three straight years, 2022 through 2024, every glaciated region on Earth lost mass, and 2023 set a record near 600 billion tonnes, the worst single year in five decades (WMO). The 2025 figures, around 408 billion tonnes, offer no real relief.

Numbers on that scale stop meaning much, so here is why they matter to people who will never set foot on a glacier. Mountains supply 55 to 60 percent of the world's annual freshwater flow, and close to two billion people draw their water from them. Two-thirds of the planet's irrigated farmland depends on mountain runoff (UN World Water Development Report, 2025). In the Andes, 85 percent of hydropower comes from mountain catchments. A glacier is a savings account that pays out in the hot, dry months when the rain does not come. As the ice shrinks, the account first overpays, with more meltwater and more flooding, and then it runs dry. Communities from Peru to Pakistan are already living through the early version of that arc. I don’t want to take away from the power of images like the polar bear on the tiny iceberg, but glaciers are more than a symbol, they are a critical source of food and water security in both the developed and developing world.

The Alps, where we will spend most of this project, are the clearest preview we know of. Even if global emissions and warming had stopped completely in 2022, the Alps are already committed to losing at least a third of their ice by mid-century, and on the trend of the last twenty years it is closer to half (Cook et al., 2023). Swiss glaciers gave up about a tenth of their entire volume in the two hot summers of 2022 and 2023. A study published in December 2025 went further and put dates on the disappearances: under the climate policies in place today, perhaps 110 glaciers would survive in central Europe to 2100, about 3 percent of the 3600+ today (Van Tricht et al., 2025). The great Aletsch breaks into pieces, the Rhône becomes a remnant, and stories like the village of Blatten being destroyed in moments by a collapsing glacier will become regular news .

So, why build our glacier archive? We decided to step away for a season to build something we have talked about building for years but have never had the time (or AI enabling technology) to do. The United Nations made 2025 the International Year of Glaciers' Preservation. The attention is welcome but the translation into something a non-specialist can see and feel is still missing.The Glacier Archive Project is an independent effort to document and communicate the changing state of glaciers, using repeat photography, open data, and a set of AI tools we are building as we go. The plan is to put the result into the public domain, an archive anyone can use, because the science here is excellent and well funded, yet most of it lives in journals that ordinary people never open or photographers charge license fees to use.

Repeat photography is the heart of it, and it is beautifully simple. You find where a photographer stood five, ten, fifty, or a hundred years ago, you stand in the same spot, you take the same frame, and then even a kindergartener could play “Spot the Difference.”

Over the next twelve weeks we will move through archival research, fieldwork in the mountains, and a final synthesis, and we will post as we go, including the parts that do not work! Next time we will get into the history of glacier photography and the specific images we hope to match.

Glaciers keep an honest record. Our aim for this project is to help a few more people learn to read it.

The Glacier Archive website is now live.

This site will serve as the public home for the Glacier Archive Project, an effort to document glacier change through repeat photography and field observations. Over the coming months we plan to revisit historic glacier viewpoints and recreate photographs taken decades or even more than a century ago.

The goal is simple: build a visual record showing how glaciers have changed through time and make those comparisons accessible to the public.

The project is currently pending final approval for the upcoming field expedition. Once confirmed, this site will host journal updates from the field, photo comparisons, and documentation of the locations visited.

More updates will follow soon as planning progresses.