Polly Higgins, one of the most inspiring figures in the green movement, has died aged 50.

Higgins, a British barrister, led a decade-long campaign for “ecocide” to be recognised as a crime against humanity. She sold her house and gave up a high-paying job so she could dedicate herself to attempting to create a law that would make corporate executives and government ministers criminally liable for the damage they do to ecosystems.

The destruction of the Earth is a crime. It should be prosecuted | George Monbiot Read more

Such a legal instrument could be a powerful tool for conservationists, climate campaigners and activists trying to stop air and water pollution, but earlier proposals for this to be included in the Rome statute on international crimes against humanity were dropped in 1996.

Ten years ago Higgins set out to revive the idea. She wrote a book, Eradicating Ecocide, lobbied the United Nations law commission, organised mock trials and established a trust fund for “Earth protectors”. Although the law has yet to be recognised, momentum is growing as a result of the ongoing climate crisis and growing evidence that major companies lobbied against policies that could protect people from pollution and other environmental harm.

On her organisation’s website, Higgins lamented the continued absence of a law that she believed would change the world. “There is a missing responsibility to protect … What is required is an expansion of our collective duty of care to protect the natural living world and all life. International ecocide crime is a law to protect the Earth.”

Higgins grew up on the shores of Loch Lomond and childhood discussions with her meteorologist father and artist mother were often about green issues. According to an interview with the Scotsman, her parents were initially shocked that their daughter had entered the legal profession, but Higgins later said: “The Earth is in need of a good lawyer.”

Several other legal organisations are now fighting for the environment in the courts, with occasional successes such as the Urgenda case in the Netherlands, in which a judge ruled that the government’s efforts to fight climate change were inadequate and emissions cuts must be stepped up.

Campaigners say an ecocide law would take this and other campaigns to protect nature to new levels. The Guardian columnist George Monbiot wrote that it could make the difference between a habitable and uninhabitable world by shifting the balance of power and forcing executives to think twice about actions that might damage the planet.

After discovering she had an aggressive form of cancer and had only weeks to live, Higgins told Monbiot that the work she pioneered would go on after her death. “My legal team will continue undeterred,” she said.

“But there are millions who care so much and feel so powerless about the future, and I would love to see them begin to understand the power of this one, simple law to protect the Earth – to realise it’s possible, even straightforward. I wish I could live to see a million Earth protectors standing for it – because I believe they will.”

On social media, tributes and condolence messages were sent by a wide range of groups and individuals, including philosophers, human rights campaigners, lawyers and Extinction Rebellion activists.

The author and activist Naomi Klein tweeted: “She devoted her life to changing broken laws that have failed so miserably to protect the natural systems on which we all depend. Her work will live on.”

Kate Raworth, a teacher at the Environmental Change Institute of Oxford University, said she was devastated by the loss of the brilliant, pioneering legal campaigner. “May bright young lawyers worldwide be inspired to continue her essential work,” she tweeted.