The melting of a glacier in the Peruvian Andes, which is raising the risk of flooding for about 120,000 nearby residents, is being caused by man-made global warming, scientists said on Thursday, providing new evidence for an ongoing climate lawsuit.
Peruvian farmer Saul Luciano Lliuya lives in the town of Huaraz below the Palcaraju glacier that is pushing the waters of Lake Palcacocha dangerously high. He sued German energy utility RWE in 2015 over its role in fuelling global warming.
Lliuya has argued that greenhouse gas emissions from RWE’s coal-fired power plants are partly to blame for melting the glacier, producing water that threatens to flood his home.
The case was admitted by a German regional court in Hamm in 2017.
The court said it would seek evidence on whether emissions from RWE plants could be shown to have contributed to global warming and consequently the glacier’s melt – and if that put Lliuya’s home at risk of flooding.
RWE, Germany’s biggest electricity producer, has repeatedly dismissed Lliuya’s complaint as unfounded, saying a single emitter could not be held responsible for global warming.
Yet the farmer’s case may be supported by new findings published in Nature Geoscience on Thursday by scientists at the University of Oxford and the University of Washington (UW).
“The glacier has retreated dramatically,” said co-author Gerard Roe, a UW professor of Earth and space sciences.
“All of our analysis points to the fact that the retreat is essentially all due to the impact of human activities over the industrial era,” Roe told the Thomson Reuters Foundation.
Since the start of that era, from 1880 onwards, the length of the Palcaraju glacier has halved from about 4.5 km (2.8 miles) to its current length of about 2 km, driven by higher temperatures in the region, Roe said.
Using a technique developed by UW, scientists examined the relationship between warming temperatures in the region – which have risen by 1 degree Celsius since 1880 – and the long-term retreat and melting of the glacier that have caused nearby Lake Palcacocha to expand, presenting the risk of an outburst flood.
“We found that human influence on climate, through greenhouse gas emissions, is responsible for virtually all of the warming that has been observed in the region,” said Rupert Stuart-Smith, lead study author and doctoral student at Oxford.
In 1941, an outburst flood from the same lake – which the new study also found to be influenced by human-induced climate change – killed at least 1,800 people.
UW and Oxford said it was one of the earliest fatal impacts of climate change to have been identified globally.
The study’s findings could support Lliuya’s case, backed by environmental non-profit Germanwatch, as the lawsuit centres on whether a company can be held financially responsible for the contribution of its carbon emissions to the effects of climate change in other parts of the world.
Noah Walker-Crawford, an external advisor to Germanwatch on climate litigation, said lawyers representing Lliuya will present the latest research to the German court as evidence.
Neither Lliuya’s legal team nor Germanwatch had any involvement in the research or provided any funding, he added.
“As scientific evidence, this provides support to the legal argument that RWE is partially responsible for climate risk in Peru, as the company has made a substantial contribution to global warming through its emissions,” said Walker-Crawford, an anthropologist at Britain’s University of Manchester.
“This is the first research of its kind, as it links a very local impact – the retreat of one specific glacier and subsequent flood risk – to global warming,” he said.
Court-appointed experts plan to visit Peru to study flood risk around the glacier, but have been delayed due to the COVID-19 pandemic, he said, adding it could take two or three years for a verdict to be reached.
Lliuya’s claim seeks about $20,000 which would help fund a $4-million local government scheme to prevent flooding from the lake and build flood defences.
Thom Wetzer, a professor and founding director of the Oxford Sustainable Law Programme, said a number of new lawsuits were attempting to hold companies with significant emissions responsible for the costs of climate change.
To succeed, those claims would require “rigorous scientific evidence quantifying the links between emissions and impacts” of warming, as provided by the Peru study, he said.
“It is now up to litigators to translate the science into high-impact legal arguments,” he added in a statement.