More than 1.6 million people have signed an online petition to take the French state to court for not doing enough to fight climate change, The Associated Press reports.

Greenpeace, Oxfam and two French environmental groups launched the petition last week. Their signature drive received exceptional support in just a few days, including from film stars Marion Cotillard and Juliette Binoche.

Greenpeace France director Jean-Francois Julliard said on France’s BFM television Monday that the groups hope for an eventual court ruling requiring France to further lower carbon emissions.

Julliard says the legal effort could take years, but cited a similar, successful effort in the Netherlands.