Brazil's Atlantic Forest Records Lowest Deforestation in 40 Years

Brazil's Atlantic forest, the country's most threatened biome, last year recorded its lowest level of deforestation since monitoring began 40 years ago, a new report shows.

The forest is Brazil's most populous biome, and home to 80% of the population and major cities such as Rio de Janeiro and São Paulo. In 2025 it recorded 8,658 hectares of deforestation, marking the first time it has fallen below 10,000 hectares since 1985.

Environmentalists have welcomed the results, which they say could even lead to “zero deforestation” in the Atlantic forest within just a few years, but warned of potential risks that could reverse the downward trend of recent years.

One is the recent approval of the so-called “devastation bill” in Brazil's congress that drastically weakens environmental law.

The other is the prospect of a far-right government, opposed to environmental protection policies, returning to power in the October presidential election: Flávio Bolsonaro, the senator and son of the former president Jair Bolsonaro, is tied in the polls with the current president, Luiz Inácio Lula da Silva, who will seek re-election.

“It's a very worrying scenario,” said Luís Fernando Guedes Pinto, executive director of the NGO SOS Mata Atlântica, who added that, with a victory for Bolsonaro, “Brazil could lose the opportunity to be a global environmental leader”.

During the elder Bolsonaro's 2019–23 administration, his policies led to a historic surge in deforestation and a gold rush into Indigenous lands. Many scientists, environmentalists and activists fear such rampant destruction could return if his son, who has vowed to follow his father's playbook, comes to power.

“We have seen the return of a policy to combat deforestation under the current government … [If Flávio Bolsonaro wins] there is a risk of returning to a path of rising deforestation across all biomes, because his political group – the same as his father's – is anti-science, denies climate science, and sees nature and forests as obstacles to development,” said Pinto.

Two new sets of data were released on Thursday, both based on monitoring carried out in partnership between the NGO and other organisations.

One, conducted over four decades, showed a 40% drop in deforestation from 2024 to 2025, falling from 14,366 to 8,658 hectares. Under Bolsonaro's presidency, it exceeded 20,000 hectares in each of his final two years in office.

The other dataset showed a 28% decline, from 53,303 to 38,385 hectares. This monitoring has been conducted only since 2022, and last year's figure was the lowest.

The difference between the two monitoring systems, according to the NGO, stems from the satellites they use – the newer system is more precise, while the older one provides a longer historical record.

Despite the decline, “deforestation is still high” in the biome, said Pinto, adding that “in the Atlantic forest, every fragment lost makes a huge difference”.

The biome is the country's third largest, behind the Amazon and the Cerrado savanna, but is by far the most urbanised and degraded. The Atlantic forest now has only 24% of its original forest cover, while the Amazon retains about 80% and the Cerrado around 50%.

Even so, if the downward trend of recent years continues – which the NGO attributes to a combination of public pressure, civil society mobilisation, environmental policies and enforcement actions – Pinto believes the biome could reach “zero deforestation” within the next three years.

Standing in the way, however, is the new law, considered the greatest setback to Brazil's environmental legislation since licensing first became a legal requirement in the 1980s.

Lula vetoed parts of it, but his vetoes were overturned by the largely conservative congress at the end of 2025.

The new law removes the requirement for prior approval from the federal environmental agency for states to authorise deforestation, leaving the decision entirely to local authorities, and its constitutionality is being challenged in the supreme court.

Malu Ribeiro, director of public policy at SOS Mata Atlântica, said the law is a “distortion” that puts Brazil at odds with the Paris agreement and could exacerbate climate disasters. “Weakening protection instruments now risks everything we have spent years building,” she added.