In the 41 years since he was born in the shadow of the Cordillera Blanca, Peru’s largest glaciated mountain chain, Saúl Luciano Lliuya has watched the range’s glistening peaks darken as their snow and ice have gradually receded.

A mountain guide and small farmer, he’s now the plaintiff in a novel lawsuit filed in Germany over the role of emissions by a German power company in the melting of Peru’s glaciers. His lawyer says that if the suit succeeds, it will be the first time a major utility has been held responsible for the climate-change impact of its greenhouse-gas emissions.

Luciano, who grew up in the small village of Llupa, now lives in nearby Huaraz, an Andean city of about 120,000 people that is the capital of the country’s central Ancash region.

High in the peaks above Huaraz is Lake Palcacocha, which has swelled as glaciers on the mountainsides that cradle it have retreated. As the climate warms, there is a growing risk that an enormous block of ice could break loose and crash into the lake, causing a wave that would swamp Palcacocha’s earthen dike and send water, mud and rock cascading down the mountainside.

The danger is not hypothetical. Such events—known as glacial lake outburst floods, or GLOFs—have occurred before in the Cordillera Blanca. Aerial photos show that various towns along the Santa River, which flows through Huaraz, are built on sediment fans from past floods. A GLOF in 1941 obliterated part of Huaraz, killing 1,500 to 4,000 people, historians estimate. Some 40,000 people now live in the path carved by that avalanche. Among them are Luciano and his family.

The lawsuit, the brainchild of the Bonn-based green group Germanwatch, stemmed from a trip members of the organization took to Lake Palcacocha after the 2014 global climate summit in Lima. Luciano was Germanwatch’s guide on that visit. The suit, filed in 2015, targets the German energy company RWE, claiming that the company’s greenhouse gas emissions are contributing to global warming, causing Peru’s glaciers to melt and putting Luciano’s house in danger of another GLOF. The lawsuit says RWE ranks high among European power companies in carbon intensity, due to its longstanding use of coal and lignite.

Estimating RWE’s contribution

Peru still has the world’s largest expanse of tropical glaciers, but the ice fields have been shrinking by about 10% every decade since the 1970s. Because RWE emits 0.47% of the world’s greenhouse gasses, the suit says, it should pay 17,000 Euros, or 0.47%, of the cost of shoring up the dam that contains Lake Palcacocha.

The case advanced a step in May, when two members of the three-judge panel handling it conducted an on-site inspection, visiting Luciano’s home and making the trek up the mountain to Lake Palcacocha, at 14,967 feet (4,562 meters) above sea level. The Essen district court must decide two questions, plaintiffs’ attorney Roda Verheyen said on May 30, following the visit. The first is whether there is a real risk to Luciano’s house, and the second is whether that risk is caused by climate change.

“Nobody who was there could question the risk,” Verheyen says. Whether it is imminent, however, is for the court to decide.

A ruling for the plaintiffs would break ground in holding major greenhouse-gas emitters responsible for their contribution to climate change, says Christoph Bals, Germanwatch policy director. That could lead to higher risk ratings for energy companies and other major emitters, giving impetus to the quest for political solutions to the climate emergency.

“We are speaking about a global neighborhood in this lawsuit,” Bals says.

Markus Krebber, RWE’s CEO, took a different view in remarks on his company’s website. “It is extremely difficult to prove this kind of causality in global developments,” he said. “If this case is decided in favor of the farmer, we might as well all end up suing each other for a few cents each. It just isn’t reasonable.”

While the court case plays out in Germany, steps are being taken locally. Signs near Huaraz’s main plaza show evacuation routes in case of an outburst flood. And staff from Peru’s National Institute for Research on Glaciers and Mountain Ecosystems (Inaigem) have been raising awareness in high-risk neighborhoods.

After the 1941 Huaraz disaster, engineers installed systems that drain water from Cordillera Blanca glacial lakes when lake levels rise dangerously. More recently, high-tech warning systems with microphones, video cameras and motion sensors have been tested that, in the event of a flood, would trigger an alarm, giving downslope residents a short time to flee.

Prickly reception

But those devices have also raised local suspicions. A system installed in 2013 above the town of Carhuaz was destroyed three years later by local residents who blamed it for a drought. (See "Learning from flood-alarm system’s fate" —EcoAméricas, April 2017.) A system being set up at Lake Palcacocha before the onset of the coronavirus pandemic is not yet operational. The wariness stems from a general distrust of authorities, says Luciano, who has fielded doubts from neighbors and even some relatives who feared his lawsuit was an effort to profit by selling Palcacocha’s water.

Scientists have also become the focus of suspicion. An international expedition in 2019 to drill an ice core from Peru’s highest peak, Mt. Huascarán, was cut short when local residents accused the researchers of prospecting for gold or stealing the mountain’s heart.

Still, some progress has been made. Lake Palcacocha’s dike, a natural moraine, is equipped with a battery of siphons designed to keep the water level in check. There are plans to build a newer, reinforced dam, although Luciano would like to see a multipurpose system with water storage for small farmers.

Meanwhile, scientists are learning more about the effect of climate change on the Cordillera Blanca’s glaciers and downslope environment. A prime goal of that work is to help local residents adapt, says Bryan Mark of the Byrd Polar and Climate Research Center at Ohio State University, who has studied Peru’s retreating glaciers for 25 years. The warming climate causes changes not only in the amount of water flowing from mountain lakes, but also in the quality of that water, which can become more acidic if it flows over exposed rock.

Mark says that besides preparing for disasters, it is crucial to understand how much glacial meltwater is carried by rivers and streams and how much enters the groundwater in order to plan for the water needs of growing cities.