Brazilian officials served up an array of plans and figures at the recent COP28 climate summit in Dubai, presenting itself as a world leader, on track to protect its forests and the people who live there.

But on Thursday, Brazil’s Congress approved a law that threatens Indigenous people’s rights to most of the land they inhabit or claim, potentially opening vast territories to deforestation, farming and mining.

The new law requires that Indigenous people must provide concrete evidence that they occupied the land they claim on Oct. 5, 1988, when the country’s current Constitution was enacted — a requirement that many of them have little or no hope of meeting.

Under the new rule, not only can Indigenous land claims currently going through the legal process be thrown out for lacking such documentation, but established legal protections for Indigenous territories can also be challenged in court and rescinded.

“We have watched the entire world at COP28 saying that we need to change the direction the planet is taking,” said the leftist congressman Tarcísio Motta, who voted against the bill, “but congress has just withdrawn the rights from the people who point to the future of the planet.”

Studies have repeatedly shown that protected Indigenous territories have helped prevent Amazon deforestation, meaning the forest can better store carbon to fight climate change.