Words by Juliette Becquet, translated by Stéphanie Major
Photo Credit: Huw James

In collaboration with POW Europe and icebreaker, Juliette is currently working on the Glacier footprints project. We caught up with her to find out more about the impact of melting glaciers on the outdoor community, global biodiversity, and water resources.

In what ways are glaciers essential to local and global biodiversity? 
To date, my research mainly focuses on mountain rivers in the French Alps, whether they are fed by glacier melt, snowmelt, rain or groundwater. Having studied many alpine rivers with very different environmental characteristics, I am always surprised to find aquatic insects, even in rivers close to glacier mouth, with turbulent, cold and turbid waters. More properly called macroinvertebrates, these organisms represent the dominant macrofauna in alpine streams, as fish fauna becomes scarce in high mountains. They are a key element in the food chain of mountain river ecosystems, not just because they are the basis of fish diet (when present), but also because they are the prey of some birds and amphibians, and above all they help keep the rivers clean by feeding on algae and suspended organic matter. More generally, glaciers can be considered as extreme environments, but there will always be adapted species that need these harsh conditions to live and reproduce. Another example is the red microalgae growing on snowpacks, sometimes called “the blood of glaciers”. 

Glaciers are therefore crucial to local biodiversity. However, they are also essential many kilometers away, as they feed rivers downstream, all the way to the sea or ocean. Along its journey, the glacier-fed river will grow as it encounters tributaries, and serves as a habitat, larder or simply a water resource for thousands of aquatic (e.g. insects, fish, algae) and terrestrial (e.g. insects, amphibians, birds, mammals, vegetation) species. By transporting sediments and organic matter to its mouth, the river will eventually influence phyto and zooplankton in the sea or ocean, with cascade reactions throughout the marine food chain. It is hard to imagine how important glaciers are for all forms of life, including human life, and not just in the nearest valley. This is why the Glacier footprints project has been initiated, in collaboration with the nonprofit organization Protect Our Winters Europe (POW) and the icebreaker clothing brand. Through a White paper and a film called Downstream, the project aims to raise awareness among the general public and the outdoor community about the consequences of glacier retreat caused by climate change on the glacier-fed rivers, water resources, human activities and biodiversity. To learn more about the challenges facing these rivers, we interviewed scientists, athletes, farmers, anglers and others. 

What animals or plant species are most threatened by glacier melting?
The anthropogenic climate change we are currently facing is amplified in alpine environments, particularly in summer. As average air temperatures rise, the quality of precipitation is modified (more rain, less snow), leading to a reduction in snow cover and a retreat of glaciers. Although observed since the end of the Little Ice Age (mid-19th century), glacier retreat has accelerated over the last 50 years. At global scale, glaciers are projected to lose between 20% and 52% of their mass by 2100 relative to 2015, depending on temperature change scenarios. 

Often thought of as water towers, glaciers play an essential role in the water cycle, delivering water when we need it most: the summer dry season (for temperate and continental climate areas). Their disappearance therefore has major consequences for water resources and everything downstream. After a first increase in glacier meltwater, glacier shrinkage leads to significant glacier runoff reduction, resulting in major flow changes in the rivers they feed, which become more dependent on precipitation, more variable over time and less predictable. 

These hydrological alterations modify the river hydraulic conditions, sediment transportation, morphologies, and physico-chemical conditions. In turn, modifications in local habitat conditions induce changes in aquatic biodiversity. Of course, it depends on each case, but in general, decreasing flows are associated with a decrease in flow velocity and an increase in water temperature, disadvantaging rheophilic (i.e. preferring fast-flowing water) and cold-adapted species. This is true both near the glaciers (e.g. macroinvertebrates) and much further down (e.g. salmon). Most of the losers of glacier retreat are specialist species, uniquely adapted to glacial conditions, whereas the winners are generalist species colonizing from downstream. Although decreasing glacier influence generally favors more abundant and diverse local aquatic communities, the arrival of new species increases competition with alpine species, adding a further constraint to them. In addition, the loss of glacial meltwater contribution to alpine streams homogenizes environmental conditions among rivers at the catchment scale, leading to a reduced variability in communities, so a decreased global diversity. 

Infrastructures on rivers, such as dams, can also accentuate the effects of climate change. For the film Downstream, directed by Huw James and produced by Dan Yates, we traveled along the main tributary of the Columbia river, the Snake river, which starts in the Yellowstone National Park, United States, and flows 1700 km before joining the Pacific Ocean. Halfway through our trip, we met Stephen Pfeiffer, wild fish and hydro manager at Idaho River United, a non-profit organization that aims to protect and restore rivers and aquatic species accross Idaho. He explained to us that in the lower Snake and Columbia rivers, the presence of dams leads to higher water temperatures, particularly in summer, due to stagnant reservoirs. As a result, all salmon and steelhead populations are declined and listed as threatened or endangered.

Everything in the world is interconnected: how can the melting of glaciers and polar ice caps affect the daily lives of people globally? How much ice have we lost globally in the past 100 years? Is it accelerating everywhere? 
Glaciers cover about 10% of the Earth’s land area: 9.5% are represented by ice caps, and 0.5% by mountain glaciers. All are retreating rapidly and many will disappear within decades. Glacier retreat is a worldwide phenomenon, increasing the threat to biodiversity and water resources for hundreds of millions of people, mostly in developing countries. In the current context of climate change, around 24% of the world's lowland population will be critically dependent on water supplies from mountain regions by 2050, compared with 7% in 1960. 

As I said previously, glacier shrinkage can have consequences very far away from its mouth. Moreover, in addition to having a direct impact on the hydrology of alpine rivers, climate change is also leading to an increase in anthropogenic pressures on rivers, linked to rising water demand for agriculture, drinking water, hydropower, nuclear power plant cooling, etc. For the film Downstream, we also traveled along the Rhône river that starts at the Rhône glacier in Switzerland and ends in Camargue, France, at the Mediterranean Sea. 800 km downstream from the glacier, we met Camargue rice producers, Bernard Poujol and Philippe Dupuy, who explained to us how changes in the Rhône river flows, combined with rising sea level, are impacting the river's biodiversity and morphology, and contributing to soil salinization. As a result, agricultural practices, in particular irrigation techniques, have to be adapted, which means being inventive to cope with these new changes. 

What glacier(s) have you studied the most yourself? What changes did you see in the last few years? 
In my research, I was interested in the French Alps glaciers, which are shrinking particularly rapidly: -24% drop in area from 2003 to 2015. In particular, I looked at the Saint-Sorlin glacier to better understand what happens in the river it feeds, and this glacier’s area decreased by 42% between 1952 and 2015, and will shrink by a further 50% by 2035. Closer to where I grew up, in the Arve river catchment, downstream from the Mont-Blanc massif (Europe's highest peak), glacier area could shrink up to 44% by the end of the century, resulting in a 40% reduction in the summer flow of the Arve river. I think one of the most striking examples here is the Mer de Glace glacier, whose moraine configuration and sporting appeal make glacier retreat particularly visible. The area is so popular with tourists, and so well known for showing the effects of climate change, that a gondola has been built to go down to the glacier mouth, which is constantly retreating year after year.

What consequences does the melting glaciers have on the outdoor community? Are we seeing the last years of sports like summer skiing? 
The glacier retreat is having a major impact on outdoor activities and our approach to the mountains, particularly as it increases natural risks (e.g. rockfall, avalanches). Although the mountains have always been a risky environment for which we need to be prepared, climate change is game changing and practices need to be adapted, for example regarding routes or passage times. 

In most parts of the world, the number of days available for summer glacier skiing is decreasing, forcing teams and ski clubs to travel further to take advantage of the best possible conditions. As a ski instructor, I have been immersed in the world of skiing since I was a child, and I have seen and experienced a big difference over the last twenty years. Although this is more about snow than glaciers (but snowpacks also represent a significant water storage and are correlated with glaciers), things are changing in the ski resort where I taught for over 10 years. The lower altitude slopes have to close more and more often, and the low quantities of snow make the slopes steeper and more difficult. For now, the main response of ski lift operators to these changes is the intensification of snow production and the optimization of snow grooming (which also impact water cycle). However, these solutions are not viable in the long term and we will have to be inventive about what the mountains of tomorrow will look like to satisfy both the ecosystem and human needs. As a mountain lover, I understand that these changes can be scary because they affect our identity. However, I think we must seize the opportunity to invent something new, and the sooner we do it, the smoother the process will be. 

It's clear we need to move away from fossil fuels to help stop the melting of glaciers. What other preventative measures are scientists looking at, or are possible or actionable today? These giants are shifting and changing in real time. But what gives you hope for their preservation? 
All the most advanced knowledge on climate change is contained in the IPCC (Intergovernmental Panel on Climate Change) report, freely available online. This is a colossal, rigorous scientific work, written and reviewed by thousands of scientists, in which almost every country in the world is represented. The Sixth Assessment Report of IPCC consists of 3 reports, one on the physical science basis of climate change, one on the impacts and one on mitigation, each between 2,000 and 3,000 pages long. There are summaries of just a few dozens of pages, and a large number of organizations (such as POW!) are doing a remarkable job of synthesizing this information. 

The reason I mention this is to show that there is one great thing about climate change: we know exactly what it is, where it comes from, what the impacts are and what the solutions are. And the other good news is that it does not require any great scientific breakthroughs: although new technologies can help us adapt to climate change, the quickest and simplest way to mitigate climate change and glacier retreat is to change our lifestyles, notably by a significant reduction in our consumption of materials and energy, including meat and fossil fuels, combined with strong political decisions and corporate commitment. 

I remain optimistic when seeing the ambition and passion shown by organizations such as POW in advocating for action on climate, and businesses such as icebreaker in searching for sustainable solutions to business. I am also inspired by the drive and determination of young people in the climate movement and their determination to create a better world than has been left to them.