Floods from melting alpine glaciers appear to be a more obvious threat from global warming. Instead, they have become the most controversial, even among scientists studying the subject. Now, for the first time, the risk of flooding in a particular city has linked to climate change-induced melting of a glacier above it, in a study that could determine a significant court case worldwide.
The city of Huaraz sits at it is the Palcacocha Lake. Large amounts altitude of 3,000 meters (10,000 feet) in the Peruvian Andes. More than a kilometer above of ice fell into the lake in 1941 and massive floods broke out, killing at least 1,800 people in the city.
Engineering work has offered some protection to the city since the 1970s. However, the Palcacocha Lake, which feeds the Palcaraju Glacier, has been rapidly receding since 1995, leaving the lake behind and widening into a basin. There are fears that efforts to mitigate this melting flood have once again threatened Huaraz.
A court case is underway based on allegations that greenhouse gas emissions blamed for the hazardous situation in Huaraz and therefore the world’s biggest polluters should paid to solve the problem. Gerard Rowe, a professor at the University of Washington, and colleagues has developed a method for examining the effects of global climate on individual glaciers. “The scientific challenge was to provide a clear and unambiguous assessment of the physical connection between climate change and the risk of altered flooding,” Rowe said in a statement.
Robert Stewart-Smith, a doctoral student at Oxford University, applied Rowe’s method to Palcaraju and published research in Nature Geoscience. Rowe and Stuart-Smith observed that rainfall in the region has only recently changed, so the retreat almost entirely caused by local temperature trends – of which at least 85 percent are the result of human activity.
“We have come to the conclusion that it is virtually certain (> 99% probability) that the retreat of the Palcaraju Glacier at the present time cannot be explained by natural variability alone,” the paper noted. Burning every ton of carbon dioxide or methane coal or crushing cows further increases the hazards faced by the atmosphere.
“We believe that our study was the first to assess the complete set of connections between ethnographic climate change and the risk of flooding from the altered glacier lake catastrophe.” “The methods used in our study can certainly be applied to other glacier lakes in the world.” “Seriously, our investigations establish a direct link between emissions and the need to implement protective measures now, as well as any damage caused by future flooding,” Stuart-Smith added.
Plaintiff Huaraz resident Saúl Luciano Lliuya lost in the lower court. Even if the German regional court hears the case and accepts the paper evidence, it is not certain that they will have to pay compensation to the specific defendant – the power generator RW – – to Liu. Nevertheless, science is a necessary step.
Of the thousands of pages of evaluation on the intergovernmental panel of the Fourth Assessment Report on Climate Change, the only thing that successfully challenges critics is the melting of the Himalayan glaciers. The science found in this matter that any decision about what would happen was very uncertain. Rowe’s work may change this for the future, giving us a clear idea of what dangers we will face on this front.
