A man walks between two presidential campaign materials pegged to a line

Brazilians will decide on 30 October if Jair Bolsonaro will get a second term.Credit: Adriano Machado/Reuters

When Brazil elected Jair Bolsonaro as its president four years ago, this journal was among those that feared the worst. “The election of Jair Bolsonaro is bad for research and the environment,” we wrote (Nature 563, 5–6; 2018).

A populist and a former army captain, Bolsonaro charged into office denying science, threatening Indigenous peoples’ rights, promoting guns as a solution to security concerns and pushing a development-at-all-costs approach to the economy. Bolsonaro has been true to his word. His term in office has been disastrous for science, the environment, the people of Brazil — and the world.

This weekend, Brazilians will go to the polls in the second round of one of the country’s most important elections since the end of the military dictatorship in 1985. Bolsonaro is standing for re-election for the Liberal Party. His opponent is Luiz Inácio Lula da Silva, the Workers’ Party leader who was president for two terms between 2003 and 2010. In the first round of the election, held on 2 October, Lula beat Bolsonaro into second place, but by an unexpectedly narrow margin. He failed to win an overall majority, forcing the two into a run-off election.

Bolsonaro’s record is eye-popping. Under his leadership, the environment has been ravaged as he rolled back legal protections and disparaged Indigenous peoples’ rights. In the Amazon alone, deforestation has nearly doubled since 2018, with yet another increase expected when Brazil’s National Institute for Space Research releases its latest deforestation data in the coming weeks.

Like his populist former US counterpart Donald Trump, Bolsonaro ignored scientists’ warnings about COVID-19 and denied the dangers of the disease. Bolsonaro also undermined vaccine programmes, questioning the safety and effectiveness of the jabs. More than 685,000 people in Brazil have died from COVID-19. The economic crisis that followed the pandemic hit Brazilians hard.

Other similarities have been drawn between Trump and Bolsonaro — both have sought to undermine the rule of law and slash the powers of regulators.

Funding for science and innovation was waning when Bolsonaro took office, and has continued to fall under his leadership, to the point that many federal universities are struggling to keep the lights on and buildings open. Science and academia served as easy foils in an anti-elite offensive that mirrored the culture wars of the United States.

This contrasts with the situation around a decade or so before he came to power, when the Workers’ Party made big investments in science and innovation, strong environmental protections were in place and educational opportunities were expanded. Furthermore, thanks in part to a massive cash-transfer system for the poor, called Bolsa Família, people on low incomes saw gains in wealth and opportunity.

Brazil brandished its reputation as an environmental leader by ramping up environmental law enforcement and curbing deforestation in the Amazon by around 80% between 2004 and 2012. For a time, Brazil broke the link between deforestation and the production of commodities such as beef and soya beans, and it looked as if the country could pioneer its own brand of sustainable development. Much of that progress has since been undone.

In contrast to Bolsonaro, Lula has not sought to fight researchers. He has pledged to achieve ‘net zero’ deforestation and protect Indigenous lands if elected. But Lula is not without baggage. He spent 19 months in jail as a result of a corruption investigation that implicated government officials, including Workers’ Party leaders. But in 2019, the Brazilian supreme court determined that Lula and others had been improperly imprisoned before their appeal options had been exhausted. Lula’s convictions were annulled in 2021, clearing the way for him to run for president again.

No political leader comes close to anything like perfect. But Brazil’s past four years are a reminder of what happens when those we elect actively dismantle the institutions intended to reduce poverty, protect public health, boost science and knowledge, safeguard the environment and uphold justice and the integrity of evidence. Brazil’s voters have a valuable opportunity to start to rebuild what Bolsonaro has torn down. If Bolsonaro gets four more years, the damage could be irreparable.