A German court has started hearing a Peruvian farmer’s case against major energy company RWE. His lawsuit argues that global warming fueled by the firm’s historical greenhouse gas emissions ultimately poses a risk to his home.

Saúl Luciano Lliuya’s lawsuit against RWE argues that the company’s historical greenhouse gas emissions have fueled global warming, accelerating glacial melt above his hometown of Huaraz, Peru. As a result, Lake Palcacocha has swelled to dangerous levels, threatening the community with the risk of catastrophic flooding.

RWE, which has never operated in Peru, denies legal responsibility, arguing that climate change is a global issue caused by many contributors.

The lead lawyer in the complaint, Roda Verheyen, said she was “calm but hopeful.” She said that “there is no time to be lost, because the glaciers are melting every day.”

RWE “is still one of the biggest emitters of CO2 in all of Europe,” Verheyen said. “This is only a very first step — a trampoline for further cases of this kind” that could target other emitters.