This is what a century of climate change has done to France’s biggest glacier

The 'Mur de Seracs' a part of the 'Mer de Glac. Image: Getty.

Like a one-man Google Earth, on 8 August 1909, Swiss aviation pioneer Eduard Spelterini flew a gas-filled balloon from the French town of Chamonix to Switzerland – a distance of 100 miles over the Alps.

While the flight was extraordinary for being the first aerial crossing of the central Alps from west to east, it now holds a special significance of which Spelterini was unaware. The balloonist was also a photographer who captured a series of glass-plate images of the Mer de Glace (“sea of ice”) glacier that descends from the Mont Blanc Massif in a dramatic sweep.

Spelterini’s interest in recording the alpine landscape was both scientific and aesthetic, and the results are striking. This collection of images survives today as a record of the glacier that is unique in its detail and antiquity.

But crucially, they can be used to measure how much this landscape has changed in the intervening years. In 1909, no one could have guessed how significant these glaciers would become to environmental science, or just how rapidly they would be affected by rising temperatures in the century that followed.

Digital analysis

The flight over the Mer de Glace was unusual because Spelterini’s aerial photographs rarely focused on the glaciers, instead more often framing the peaks and other geological features. He was also unaware that the distribution of his photographs along the balloon’s flight path, pictured below, would make excellent material for digital analysis more than 100 years later.

The flight path of Eduard Spelterini’s balloon in 1909. Image: author provided.

By identifying common features in the photographs, which can in turn be linked to surveyed features in the landscape, a 3D representation of both the balloon flight and the historical topography can be reconstructed using photogrammetry – the science of taking measurements from photography. While the oblique angle of the photographs limits the measurable accuracy of the resulting data, compared to the vertical mapping photographs taken in the decades that followed, they still provide a unique and compelling glimpse into a past landscape.

In Spelterini’s image below, the oblique aerial view taken at a sideways angle towards the horizon gives a sense of place that is part way between the familiar ground level view and the high vertical perspective like that of a map. In the foreground the newly completed Montenvers cogwheel railway is visible, perched over the voluminous Mer de Glace glacier which leads the eye to the spires of the Mont Blanc Massif in the background.

The Montenverscog railway in the foreground was recently completed when Spelterini took this photograph. Image: Eduard Spelterini/author provided.

The photographs are carefully composed, designed to serve as both record and artwork. Their oblique angle makes them less abstracted and more relatable, despite their height above the ground and the scale of the landscape they depict. All of these factors make them an ideal point of reference for visualising the changing nature of the alpine landscape.

Follow that balloon

In October 2017, a team of photographers and researchers from the University of Dundee returned to Chamonix to replicate the path of the historic flight and recreate the sequence of photographs using a helicopter. Spelterini’s balloon rapidly ascended to around 2,000m above the Chamonix valley before passing Mer de Glace. Such heights are virtually inaccessible to unmanned drones, meaning that a manned aircraft was needed.

The results are documented in The 100-year Time-Lapse Project. GPS coordinates derived digitally from Spelterini’s photographs were used to return to the same locations to capture current-day equivalents of both his individual photographs and the 3D surface reconstruction. While the rate of change in the Mer de Glace glacier has been studied in great detail, using digital technology in this way allows for a visual comparison of the landscape then and now to reveal the staggering reduction in the ice surface that has taken place over the last century.

Credit: Kieran Baxter and Kieran Duncan/YouTube.

Today, visitors alighting at the Montenvers railway station are no longer confronted with the Mer de Glace at close range, but instead look down upon a largely empty valley and debris-covered glacier far below. Here the ice surface has dropped around 100 metres compared to its height in 1909. Scientists have calculated that, overall, the glacier has lost around 700m cubic metres of water since the beginning of the 20th century.

While the facts and figures alone should be enough to narrate the impact that the previous century of greenhouse gas emissions have had on our climate and environment, images like these help drive the point home. Eduard Spelterini was not just a pioneer of aviation but also of aerial photography as a way of better understanding the natural world. His images capture an emotive sense of place while providing insights into aspects of the landscape that are not available from the ground.

Credit: Kieran Baxter/YouTube.

Today, despite the heavy carbon footprint that comes with manned aviation, we continue to rely on aerial views to interpret our environment, from Landsat satellite imagery to low-level drone photography. By repurposing archival aerial photographs and continuing the legacy of photographers like Spelterini, with the help of current technology, we can explore new and compelling ways to visualise our rapidly changing glacial landscapes.

The ConversationAs well as serving to convince hearts and minds in the present political debates surrounding climate change, these images will also form a poignant record of magnificent landscapes that will no longer be around for future generations to experience.

Kieran Baxter, Research assistant, 3DVisLab, Duncan of Jordanstone College of Art and Design, University of Dundee.

This article was originally published on The Conversation. Read the original article.


 

 
 
 
 

Covid-19 is highlighting cities' unequal access to green space

In the UK, Londoners are most likely to rely on their local park for green space, and have the best access to parks. (Leon Neal/Getty Images)

As coronavirus lockdowns ease, people are flooding back to parks – but not everyone has easy access to green space in their city.

Statistics from Google show that park attendance in countries across the globe has shot up as people have been allowed to move around their cities again.

This is especially true in urban areas, where densely populated neighbourhoods limit the size of private green space – meaning residents have to go to the park to get in touch with nature. Readers from England can use our interactive tool below to find out how much green space people have access to in their area, and how it compares to the rest of the country.

 

Prime Minister Boris Johnson’s announcement Monday that people are allowed to mingle in parks and gardens with groups of up to six people was partially following what people were doing already.

Data from mobile phones show people have been returning to parks across the UK, and also across Europe, as weather improves and lockdown eases.

People have been returning to parks across the world

Stay-at-home requirements were eased in Italy on 4 May, which led to a flood of people returning to parks.

France eased restrictions on 1 May, and the UK eased up slightly on 13 May, allowing people to sit down in public places so long as they remain socially distanced.

Other countries have seen park attendance rise without major easing of lockdown – including Canada, Spain, and the US (although states there have individual rules and some have eased restrictions).

In some countries, people never really stopped going to parks.

Authorities in the Netherlands and Germany were not as strict as other countries about their citizens visiting local parks during lockdown, while Sweden has famously been avoiding placing many restrictions on people’s daily lives.


There is a growing body of evidence to suggest that access to green space has major benefits for public health.

A recent study by researchers at the University of Exeter found that spending time in the garden is linked to similar benefits for health and wellbeing as living in wealthy areas.

People with access to a private garden also had higher psychological wellbeing, and those with an outdoor space such as a yard were more likely to meet physical activity guidelines than those without access to outdoor space. 

Separate UK research has found that living with a regular view of a green space provides health benefits worth £300 per person per year.

Access is not shared equally, however, which has important implications for equality under lockdown, and the spread of disease.

Statistics from the UK show that one in eight households has no garden, making access to parks more important.

There is a geographic inequality here. Londoners, who have the least access to private gardens, are most likely to rely on their local park for green space, and have the best access to parks. 

However the high population in the capital means that on the whole, green space per person is lower – an issue for people living in densely populated cities everywhere.

There is also an occupational inequality.

Those on low pay – including in what are statistically classed as “semi-skilled” and “unskilled” manual occupations, casual workers and those who are unemployed – are almost three times as likely as those in managerial, administrative, professional occupations to be without a garden, meaning they rely more heavily on their local park.

Britain’s parks and fields are also at significant risk of development, according to new research by the Fields in Trust charity, which shows the number of people living further than a 10-minute walk from a public park rising by 5% over the next five years. That loss of green spaces is likely to impact disadvantaged communities the most, the researchers say.

This is borne out by looking at the parts of the country that have private gardens.

The least deprived areas have the largest gardens

Though the relationship is not crystal clear, it shows at the top end: Those living in the least deprived areas have the largest private green space.

Although the risk of catching coronavirus is lower outdoors, spending time in parks among other people is undoubtedly more risky when it comes to transmitting or catching the virus than spending time in your own outdoor space. 

Access to green space is therefore another example – along with the ability to work from home and death rates – of how the burden of the pandemic has not been equally shouldered by all.

Michael Goodier is a data reporter at New Statesman Media Group, and Josh Rayman is a graphics and data visualisation developer at New Statesman Media Group.