However grim the trajectory might seem, I`ve always believed that sense will ultimately prevail. As the great perils of dismantling the living world become increasingly obvious, even the most rapacious exploiters must come round. Nobody wants to live on a dead planet, do they?

There are – or – signs that this wasn`t just wishful thinking. Since 2015, mostly thanks to China, the area of the planet being reforested has increased, while thanks in large part to Brazil, the global rate of forest destruction has declined. The area of the Brazilian Amazon forest cleared each year is one-sixth of what it was when records began in 1988. In the past four years, as a result of Brazilian government policy, the deforestation rate has fallen by 71%. If Luiz Inácio Lula da Silva is re-elected president on Sunday, the country could reach zero deforestation by 2030. The arc of the moral universe seems to have bent towards justice.

But what my faith in human nature failed to account for was a perverse delight in destruction among a small cohort of the economic elite. There are people who appear to hate life and love death. Donald Trump`s removal of protections on public lands, the small bite – doubtless the first of many – he wants to take out of Yosemite, his assaults on the US National Park Service and the US Forest Service, his trashing of the Endangered Species Act: all are partly a response to lobbying by ranchers, loggers, frackers and miners. But this, I think, is not the primary driver.

More important to him, Ive come to believe, is a vengeful desire to hurt. I doubt Trump hates the monarch butterfly. Id be surprised if he knows what it is. But he does appear to hate people who love the monarch butterfly. Destroying the habitats on which this and many other endangered species in the US depend seems to be part of the “retribution” he promised. The New York Times was unable to find evidence that Trump has ever visited a national park. He probably doesn`t hate them either. But seemingly anything valued by the enemy – greens, liberals, socialists, feminists, anti-racists, “bureaucrats” and “blockers” – should be attacked on principle.

Wiping ecosystems off the map is an obvious demonstration of power. Extinction leaves a permanent mark, which is every dictators dream. Its also a highly effective means of hurting those who resist him: the Indigenous people and other people of colour so often on the receiving end of environmental destruction; the regulators; the scientists and the rest of the intelligentsia; above all, people who .

Caring could be seen as the far rights meta-target. The “suicidal empathy” theme now crops up repeatedly in videos, newspaper columns and speeches: a professed belief that those who care about other people or species should be destroyed by those who dont. This belief, by definition, is psychopathic. What exhausts my optimism is that, conned by shallow promises such as the use of brutal methods to address crime, people keep electing those who to it.

Physically and politically, Flávio Bolsonaro is the spitting image of his father, the jailed coup-plotter, Jair. When Jair Bolsonaro was president of Brazil, he appeared to see ecological destruction as a kind of a holy duty. The deforestation rate rose by 59% in his four years, and attacks on Indigenous people and other forest defenders, as well as invasions by illegal ranchers, loggers and goldminers rocketed. The crudest forms of extractivism – regardless of their costs, or how they might hold back all kinds of progress – were a matter of policy.

The ideology of the far right in Brazil has been described as “beef, Bible and bullets”: violence against those who resist the seizure of their resources, an ultra-conservative evangelism and the expansion of cattle ranching, which is both a potent symbol of far-right machismo and the primary driver of deforestation in the Amazon.

Jair Bolsonaro looked back with nostalgia to the military dictatorship of 1964 to 1985 – which was actively supported by the US government – during which local oligarchs could do as they pleased, and those who opposed them were tortured and disappeared. The warnings couldn`t be clearer, but Brazil seems determined to revisit its nightmares. Flávio Bolsonaro won the first round on 4 October, and is likely to become president.

If he wins the second round this week, the gleeful rampage of his supporters, catalysed by government policy, threatens not only the Amazon but the Atlantic forest in the south, the Pantanal wetlands, the Pampa grasslands and the savannah habitats of the Cerrado. This is politics as an orgy of destruction. Lets eradicate our life support systems – thatll teach the liberals!

Trump has been using all possible means to help Bolsonaro win. He gives the impression of seeing Latin America as the did – one big heap of treasure, ready for looting. The regions far-right demagogues are only to happy to help. Mass deforestation and the sudden ecosystem collapse that is likely to result offers a finality to their politics: theres no coming back from this. You Indigenous people, you greens, you carers: you`ll have nowhere left to hide. The world will be ours, even if it is a world of ashes.

What might teach us? First, it appears there is no limit to the perversity of the ruling class, which would rather there was nothing left to share than cede any fraction of the planet to the poor.

Second, that it possesses all the tools – social and traditional media, the pulpit and the gun – required to make its perversity look like common sense, or at least irresistible, as force is deployed. Third, that the only defence we have against suicidal gullibility is what the Brazilians call : raising awareness about the relations between exploiters and exploited, and the violence that underpins them. Otherwise all that is good, trusting and hopeful in humanity can be harnessed for a war against everyone and everything.

As for the idea that nobody wants to live on a dead planet, Elon Musk, with his preposterous plans for living on Mars – “Fuck Earth! Who cares about Earth?” – has killed that too. Extending the frontier of destruction, even to the point of human extinction, comes across as a matter of pride. The four horsemen ride again, not in cloaks but in stetsons and denim shirts, driving their cattle before them. George Monbiot is a Guardian columnist