In 1919, pilot and photographer Walter Mittelholzer flew over the Mont Blanc massif in a rickety propeller-driven aircraft, taking pictures that gave the world a new perspective on Western Europe’s highest mountain range. A century later, researchers have repeated his mission – and their images show dramatic changes in the landscape.

Dr. Kieran Baxter and Dr. Alice Watterson from the University of Dundee recreated Mittelholzer’s photographs of three glaciers in the French Alps – Argentière, Mont Blanc Bossons and Mer de Glace.

Then and now: Mont Blanc’s Argentière glacier.
Image: Walter Mittelholzer, ETH-Bibliothek Zürich / Dr Kieran Baxter, University of Dundee

Using a technique called monoplotting, they analyzed Mittelholzer’s pictures to determine the position of the camera before heading to Mont Blanc in a helicopter to recreate the shots.

Dr Kieran Baxter used modern technology to recreate the centuries-old images.
Image: Dr Alice Watterson, University of Dundee

The results show just how big an impact climate change is having on ice cover in the region. Hovering at a height of around 4,700 metres, just below the summit of Mont Blanc, Baxter says the scale of the ice loss was immediately evident.

But it was only when they compared the images side by side that the effect became fully visible.

Alpine glaciers, such as Mont Blanc Bossons, are melting at what scientists say is an alarming rate.
Image: Walter Mittelholzer, ETH-Bibliothek Zürich / Dr Kieran Baxter, University of Dundee

“It was both a breathtaking and heartbreaking experience,” he says. “Particularly knowing that the melt has accelerated massively in the last few decades.”

A mounting problem


Researchers say alpine glaciers are melting at an alarming rate as the planet warms. While global temperatures have risen by about 1°C since Mittelholzer took his pictures, the Alps have warmed by 2°C over the course of the 20th century.

Swiss pilot and photographer Walter Mittelholzer flies over Mont Blanc in 1919.
Image: ETH-Bibliothek Zürich

This is causing problems across the region, including on the Italian side of Mont Blanc, where a 250,000 cubic metre chunk of the Planpincieux glacier risks breaking away.


Alpine glaciers have lost as much as 40% of their surface area and half of their volume since 1850, reducing their ability to reflect the sun’s rays, and leading to more warming as the rock absorbs solar energy.

A century apart: the Mer de Glace glacier as it was in 2019, and today.
Image: Walter Mittelholzer, ETH-Bibliothek Zürich / Dr Kieran Baxter, University of Dundee

And the effects of this warming don’t stop there. The Alps are experiencing shorter snow seasons and reduced snow cover, more frequent soil water shortages and rises in the altitude at which permafrost is found.

As well as affecting local people, tourism and the economy, these changes are harming biodiversity, as the warming forces some species further up the mountains in search of the conditions they need to thrive.

What’s the World Economic Forum doing about climate change?

Climate change poses an urgent threat demanding decisive action. Communities around the world are already experiencing increased climate impacts, from droughts to floods to rising seas. The World Economic Forum's Global Risks Report continues to rank these environmental threats at the top of the list.

To limit global temperature rise to well below 2°C and as close as possible to 1.5°C above pre-industrial levels, it is essential that businesses, policy-makers, and civil society advance comprehensive near- and long-term climate actions in line with the goals of the Paris Agreement on climate change.

The World Economic Forum's Climate Initiative supports the scaling and acceleration of global climate action through public and private-sector collaboration. The Initiative works across several workstreams to develop and implement inclusive and ambitious solutions.

This includes the Alliance of CEO Climate Leaders, a global network of business leaders from various industries developing cost-effective solutions to transitioning to a low-carbon, climate-resilient economy. CEOs use their position and influence with policy-makers and corporate partners to accelerate the transition and realize the economic benefits of delivering a safer climate.

Immediate action

If global warming continues at the current rate, temperatures could go up by 3 to 5°C by the end of the century. Melting glaciers are also contributing to a rise in global sea levels.

The UN says that limiting global warming to 1.5°C could help reduce the most adverse effects of climate change. But has warned this would require rapid, far-reaching and unprecedented changes across society.

The University of Dundee researchers flew at a height of 4,700 metres to capture the images.
Image: Dr Alice Watterson, University of Dundee