He's the "Trump of the Tropics". Brazil's President Jair Bolsonaro likes guns, motorcycles and cattle ranching. On Facebook, he is the third most popular world leader. And he uses his platform to attack women, sexual minorities and immigrants.

But if the polls are correct, he is heading for a massive defeat in the election on Sunday. His challenger is former president Luiz Inacio "Lula" da Silva. Once a poor shoeshine boy, Lula became a left-wing hero before serving 19 months in prison on corruptionWhen someone abuses their power for personal gain. It often involves bribery. charges.

Last year, the Supreme Court overturned that conviction, freeing him to stand again for president. Experts say the world's fourth largest democracy is about to make a critical decision for the future of Brazil, the Amazon and the world.

The Amazon is the world's largest rainforest. It has 390 billion trees, and 1 in 10 of all animal species live there. Two-thirds of the Amazon lies within Brazil. During Bolsonaro's four years in office, an area the size of Belgium has been cut down to farm cattle.

If he wins, Lula promises, "there will be no Amazon deforestation". Bolsonaro is drafting new laws to give ranchers and mining corporations more power. Opponents call it a "destruction package" and say that Brazilian voters can prevent climate chaos.

Rainforests are giant air conditioners. They replace carbon dioxide in the atmosphere with water and oxygen. These chemical processes counteract global warming and slow climate change. Bolsonaro's critics say he is burning the "lungs of the world".

Ranchers start fires to clear land. Deforestation is turning the Amazon "into an accelerator of climate change", says researcher Luciana Gatti, "releasing more carbon into the atmosphere". Alarming research shows the Amazon is near a dangerous tipping point.

However, some say people misunderstand the rainforest's role in climate change. The Amazon is important, but it is not the Earth's lungs. "Oxygen is a red herringA misleading piece of information that draws you away from the right answer.", says climate scientist Gordon Bonan. Politicians and activists exaggerate the amount produced and most is absorbed back into the forest.¹

Deforestation shrank 65% when Lula was president, but he also built hydroelectric dams in the middle of the Amazon. And political experts warn a change at the top will only have a short-term effect. The law must punish land grabbers and give indigenousEthnic groups who are the original or earliest-known inhabitants of an area or country: for example, Native Americans in the USA. communities support to live off the forest without cutting down more trees.

And Lula has not won yet. His right-wing rival Bolsonaro is using scare tactics, comparing Lula to the authoritarianEnforcing strict obedience to authority. leaders of Venezuela and Nicaragua. Latin American expert Steven Levitsky says there is "zero evidence" that Lula threatens democracy.

But experts worry Bolsonaro may not accept defeat. He has said "something abnormal" will have happened if he receives less than 60% of the vote. "Only God will oustDrive someone out me", he told supporters.

Turbulent days may lie ahead for the world's seventh largest economy. What happens next in Brazil will be felt across the world.

Yes: Bolsonaro does not believe in the science behind climate change and wants to develop the Amazon. If his policies continue, the rainforest will become a dry savannahA large flat area covered with glass and occasional trees. , affecting the global climate.

No: Whoever wins, Brazil has already signed international pledges to end deforestation. The rainforest is important, but life in the oceans plays a much greater role in preventing climate change.

Or... One vote may not change the Amazon's fate, but it could deal a blow to democracy. Bolsonaro is accused of stoking political violence that has left one Lula supporter dead and a nation on the brink.