GABRIELA SÁ PESSOA SAO PAULO — Brazil’s October presidential election could reshape the future of the Amazon, with the winner leading the country that contains about 60% of the world’s largest rainforest — an ecosystem vital to the global climate.

Heading into the first round of voting on Sunday, the front-runners are Sen. Flávio Bolsonaro, son of former far-right President Jair Bolsonaro , and President Luiz Inácio Lula da Silva, who is seeking a fourth, nonconsecutive term.

The conservation of the Amazon has been largely absent from this year’s campaign. Still, the two men represent starkly different visions of how the rainforest should be managed, and climate and conservation experts warn that a victory by Flávio Bolsonaro could reverse the deforestation-control policies Lula restored after taking office in 2023.

During Jair Bolsonaro’s presidency, from 2019 to 2022, Amazon deforestation surged by about 60%, with over 45,000 square kilometers (17,400 square miles) cleared, according to official data. Under Lula, deforestation has fallen 45% , reaching its lowest level in more than a decade.

Lula’s policies would face resistance from a conservative Congress , where agribusiness holds significant sway. But his plan largely extends an agenda of emissions cuts and financing tropical forests .

Flávio Bolsonaro has pledged to end illegal deforestation by 2029, a year ahead of Brazil’s current target. Lula’s goal goes further: zero net deforestation by 2030, meaning any forest loss, legal or illegal, would have to be offset through restoration.

Deforestation and other land-use changes are Brazil’s largest sources of greenhouse gas emissions, which drive global warming. The stakes are especially high in the Amazon, which stores vast amounts of carbon dioxide and generates atmospheric moisture that helps regulate weather far beyond South America.

Sen. Bolsonaro has not detailed his Amazon-related policies, saying broadly that his administration would intensify efforts against environmental crime and promote conservation.

“Flávio Bolsonaro is a defender of the environment and of those who preserve standing forests and clean rivers,” his campaign told The Associated Press in a statement. It said his government would create economic incentives for conservation and restoration.

In an August interview with Jornal Nacional, Brazil’s most-watched television newscast, Bolsonaro said he did not believe in climate change, but rather in extreme weather events.

“Those are cyclical events,” Bolsonaro said. “The best way to address environmental issues is what we did during the (Jair) Bolsonaro administration: approve a basic sanitation framework to combat the sewage flowing past your front door.”Márcio Astrini, executive director of the Climate Observatory, a network of environmental groups, said deforestation could surge again if Bolsonaro followed his father’s path of dismantling enforcement and weakening protections.

“The risk we face is that Brazil could move away from a positive environmental agenda toward a position more similar to the one now adopted by the United States — one of climate denial,” Astrini said.

Experts say the key word in Bolsonaro’s deforestation pledge may be “illegal.”They warn his administration could weaken protections and expand where clearing is legally permitted, allowing deforestation to rise while technically honoring the pledge.

“Given his long history of advocating weaker environmental protections, there is concern that activities now considered illegal could simply be legalized and no longer subject to enforcement,” said Taciana Stec, a climate policy specialist at Talanoa, a Brazilian think tank.

Landowners in the Amazon generally must preserve 80% of the native vegetation on their properties. In 2019, Bolsonaro co-sponsored a bill that would have ended that requirement, describing it as an obstacle to development.

The proposal was dropped after opposition from agribusiness leaders, who feared it would damage the reputation of Brazilian soy and beef in markets increasingly wary of deforestation.

Bolsonaro’s campaign tapped Marcelo Donnini Freire, an environmental manager who held senior positions during the final months of Jair Bolsonaro’s administration, to help shape its environmental platform.

In September, Freire met with environmental organizations, including the Brazilian Coalition on Climate, Forests and Agriculture, which advocates for Brazilian leadership in the low-carbon economy.

A person who has been part of internal campaign discussions but is not authorized to speak publicly said a Bolsonaro administration would be unlikely to change current deforestation restrictions on private properties. Such a proposal would face opposition from export-oriented agribusiness and risk undermining investments in carbon projects and biofuels.

Pressure for increased clearing could persist, however, among smaller producers with little access to export markets or carbon-credit revenue.

Although Bolsonaro’s campaign told AP he would prioritize technology-driven enforcement against wildfires and environmental crimes, he has campaigned across the Amazon on promises to loosen environmental regulations.

One enforcement tool allows authorities to impose sanctions for illegal clearing based solely on satellite monitoring. Jair Bolsonaro halted the policy, and Lula restored it in 2023. A fast-tracked bill backed by Brazil’s agribusiness caucus would weaken it. Flávio Bolsonaro did not say whether he would preserve the measure.

Some Bolsonaro allies have been fined for environmental violations and campaigned against enforcement. News outlet Sumauma found that candidates across the Amazon had accumulated about $33 million in environmental fines, most of them from parties aligned with the Bolsonaros.

At a June rally in Belem, which hosted last year’s U.N. climate summit , Bolsonaro vowed to “modernize” environmental laws and ease licensing for farming, cattle ranching and mining. In August, he campaigned in the Estacao Parecis Indigenous Territory in Mato Grosso, pledging greater autonomy for Indigenous communities.

“They will decide what happens on their lands,” Bolsonaro told the Market Makers podcast. “If they want to farm or lease their territory, they will be free to do so. If they want to authorize mining on their lands, they will be able to do that as well.”“All of this will be done responsibly and with environmental safeguards, while respecting their wishes,” he added.

Indigenous territories are among the Amazon’s best-preserved areas but face growing pressure from farmers and illegal gold mining. Bolsonaro did not say whether his administration would establish deforestation rules for Indigenous lands.

In 2022, Jair Bolsonaro carried five of the nine states in Brazil’s Legal Amazon. Breno Rodrigues de Messias Leite, a political scientist at the Federal University of Amazonas, said Flávio Bolsonaro’s promises to loosen environmental protections may appeal to voters in the region who see the rules as overly restrictive and burdensome to businesses.

“Nobody here thinks, ‘There’s a forest over there, let me go cut it down,’” Leite said. “But one idea is deeply ingrained in the minds of the people who live here. First, they feel isolated . Second, when the state shows up, it comes with a heavy hand, with sanctions rather than with infrastructure.”

If Flávio Bolsonaro wins, Leite added, he could pursue policies that result in environmental damage. “He will have to respond to his electoral base, which is precisely rural producers. That sector wants further loosening of environmental regulations.”

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