DOWNSTREAM
SCIENTIFIC WHITE PAPER 
—GLACIER FOOTPRINTS

global impact of glacier loss

This scientific white paper examines the effects of climate change on three major rivers: the Rhône in Europe, the Columbia in North America, and the Waitaki in New Zealand. Although geographically distant, these rivers share common challenges related to glacier melt, water resources, and biodiversity loss. It emphasizes the importance of collective action, collaboration, and sustainable practices to mitigate the adverse effects of glacier retreat. Solutions include promoting regenerative agriculture, modernizing irrigation practices, improving hydropower management, and protecting biodiversity. Interviews with scientists, farmers, conservationists, and athletes provide firsthand accounts of how these communities are adapting to the evolving landscape.

Main Contents

Executive Summary

Introduction 
What is the DOWNSTREAM Project?

Rhône River, Europe

Location, Climate Change, Glacier Retreat
Hydrology
Biodiversity
Water Uses, Irrigation
Lower Rhône River
Power Generation: An Overview
Conclusion

Columbia River and Snake Tributary, NORTH AMERICA

Location
Climate Change, Glacier Retreat
Hydrology
Recreational Activities
Biodiversity
Dams
Conclusion

Waitaki River, New Zealand

Location, Climate Change
Glacier Retreat
Hydrology
Biodiversity
Regenerative Agriculture
Conclusion

General conclusion

References
About the Author and Protect Our Winters

General Conclusion

1. Mountain Glaciers:
Vital Water Sources for the World

Although they represent only a small part of the earth's surface, mountain glaciers are of vital importance to the rest of the world. The study of three locations, the Rhône (Switzerland and France), Columbia (Canada and United States), and Waitaki (New Zealand) Rivers, shows that mountains are water towers, supplying a large proportion of natural and anthropogenic water demand. Through a series of fascinating interviews, we illustrate the wide variety of sectors and ecosystems that depend, directly or indirectly, on rivers fed by melting ice and snow. Some of the interviews are available here.

2. Global Glacier Melt:
A Threat to Water Supply and Stability

Global melting of the cryosphere due to rising temperatures is altering the hydrology of rivers downstream, threatening the water supply of around 1.9 billion people living in or directly downstream of mountainous areas 125. In addition, climate change is also leading to an increase in the frequency and intensity of extreme weather events, such as hail, storms and droughts. Water users must therefore find solutions to adapt their activities, in order to mitigate their environmental impact while improving their resilience.

3. Shared Challenges Across Continents:
The Agricultural Sector’s Adaptation

One of the strengths of this project has been the observation that, even on the other side of the world, people and ecosystems are facing similar challenges. The agricultural sector, in particular, faces extremely variable weather conditions that force it to evolve. In order to prepare for water scarcity or heavy rainfall, some farmers are investing in more efficient irrigation systems, while others are focusing on holistic agriculture that prioritizes soil health and biodiversity (e.g. biodynamics, regenerative agriculture). All have demonstrated a strong attachment to their land, for which they feel responsible. However, the economic pressure exerted by large farms on smallholdings was seen as an obstacle to changing practices. Between climate change, economic conditions and environmental regulations, many factors can come into play locally, underlining the importance of consultation and communication between the various stakeholders.

4. Tourism in Mountain Regions:
Balancing Awareness and Impact

Recreational and tourist activities in mountain regions have also been shown to be vulnerable to glacier retreat, changing precipitation patterns and altered river hydrological and thermal regimes. Upstream, the evolution and instability of the terrain is modifying access routes and infrastructures, with tourist activities that sometimes play the “awareness card” (e.g. the Mer de Glace glaciorium, France, boat tours on Tasman Lake, New Zealand), and sometimes exacerbate global warming through their CO2 emissions (e.g. international clientele, glacier heliporting). Further downstream in the rivers, white-water sports operators keep a close eye on the hydrological conditions on which their activity depends and raise awareness among youngsters, while fly-fishing schedules sometimes have to be regulated to minimize the impact on fish, which suffer from warmer water.

5. Biodiversity at Risk:
The Ecological Chain Reaction of Glacier Loss

Humans are far from the only species to benefit from rivers fed by ice and snow meltwater, and thousands of species and entire ecosystems are also suffering the effects of climate change. Species dependent on cold, flowing water, such as salmonids and alpine macroinvertebrates, are the first to be impacted and deserve special attention for conservation purposes. This can have major cascading consequences, up to the modification of the marine trophic chain (e.g. planktons, Pacific orcas). All around the world, scientists, organizations, citizens and native people are working to document, inform and restore ecosystems, for example through citizen science, reforestation and free-flowing river restoration.

6. Hydropower:
Renewable Energy with Complex Impacts

While hydropower seems to be a good way of producing renewable energy, it has nevertheless emerged as a major factor in altering river dynamics and biodiversity, adding further pressure to the effects of climate change on ecosystems. In addition, hydroelectric dams are themselves vulnerable to hydrological changes linked to glacier retreat and decreasing snow cover. The question of renewable energies therefore remains open, and needs to be considered in the light of all factors.

7. A Call to Action:
Preserving Our Glacial Heritage

For many people, snow-capped mountains are also part of their identity and history, and it is our responsibility to preserve them. Immediate action is required to safeguard the future of the world's most important and vulnerable water towers. Protecting life in the mountains and downstream areas depends on keeping global temperature rise under 1.5 °C above pre-industrial level. Although climate change up to 2050 is essentially dependent on greenhouse gas emissions already achieved, mitigation strategies implemented today would have a significant impact on temperatures from 2050 onwards 43.

8. Understanding Climate Change:
Insights from the IPCC Report

The most advanced knowledge on climate change is contained in the IPCC (Intergovernmental Panel on Climate Change) report, freely available online. This colossal and rigorous scientific work provides all the keys needed to understand the origins of climate change, its impacts, and the solutions for mitigating and adapting to it. Scientists agree that this means changing our lifestyles, and in particular reducing our consumption of materials and energy. This implies a reduction in fossil fuel-based transport, meat consumption and industrial products, in favour of more eco-friendly mobility, plant-based food and short supply chains. Through their lifestyles and their right to vote, citizens play a major role in the ecological transition, but this must go hand in hand with strong political decisions, as well as a commitment from businesses, for example via the regenerative economy.

9. Citizens, Politics, and Business:
Keys to Ecological Transition

“DOWNSTREAM” is not just about what happens further down the river, it is also about what happens after us in time, about the world we leave to future generations. 

INTERVIEWS

Our interviewees are distinguished experts from diverse fields, contributing critical insights to the DOWNSTREAM project. Scientists, farmers, conservationists, and athletes—each of them brings firsthand experience and professional expertise to address the challenges of glacier retreat and its impact on glacier-fed rivers.

Pr. David Norton

Ecology and Conservation Biology

Véronique and Didier Ançay

Agricultural Engineer, Winemaker