It is depressing to think that for the first time since the return of democracy in 1985 Brazilians have elected a far-right president of the republic. Jair Bolsonaro, a seven-term lawmaker and former army captain, represents a clear and present danger not only to his country but to the planet. At home he has defended dictatorship and torture and joked about killing his leftwing opponents. He has a history of denigrating women, gay people and minorities. The president-elect promises to bring order by spreading chaos with a relaxation of gun laws. This will cost lives in a country that already records more than 60,000 murders a year. In a familiar but chilling pattern, Mr Bolsonaro successfully pitched himself as the anti-establishment candidate, appealing to voters fed up with political graft and violent crime. There’s every reason to think that Brazilians who voted in haste for Mr Bolsonaro will repent at leisure.

Mr Bolsonaro’s programme, if taken seriously, and his environmental utterances, if taken literally, amount to a threat to humanity. Brazil’s new president takes office in January, in charge of the world’s lungs, the Amazon, and the world’s breadbasket, the Cerrado savannah. He will be able to decide the course of the battle against climate change at a critical point. The signs are not good. It is thought that we have 12 years to prevent the dangerous destabilisation of Earth’s climate because of the way we live. Our patterns of existence have already led to widespread annihilation of wildlife, a disaster so large that it threatens civilisation. Yet Mr Bolsonaro’s key election pledge was to put his presidency behind Brazil’s huge agri-corporations. He favours business over biodiversity and calls for pro-market ways of exploiting Brazil’s natural resources, notably coming out against the policy of reserving the 12% of the country’s land for indigenous tribes. The far-right president-elect has also promised to weaken the enforcement of environmental laws, while criminalising activism. It is a package of measures that will not reform the model of capitalism that is slowly boiling the atmosphere, but turbocharge it.

Mr Bolsonaro says he will not scrap the Paris climate agreement, where Brazil set itself ambitious climate targets, as long as he gets assurances that his country would not cede sovereignty to native tribes or international jurisdiction over the Andes mountains, Amazon rainforest and Atlantic Ocean. This is a contradiction that will prove impossible to resolve: Mr Bolsonaro’s policies will help pave over the rainforest – with new highways and dams promised in the Amazon basin – and make it all but impossible for Brazil to reduce its carbon footprint. Until now Brazil has been, on balance, a moral force for the environmental good: largely resisting siren calls to exploit its vast natural resources for shareholder value, while bringing together rich and poor nations during climate talks. It was the frontrunner to hold the next UN climate talks. Now, instead of helping, the world’s fourth largest democracy looks like it will do irreparable harm.

With the US administration run by climate-change sceptics and China tacking away from its green stance, Europe must take a lead. The EU has a hand to play with Brazil. Deforestation is largely driven by demand for land to grow soybeans – exported to feed livestock – and to expand cattle farms. The EU is the biggest foreign investor in Brazil. Latin America’s largest economy is the biggest exporter of agricultural products to Europe. There is a strong case for new European laws to guarantee that no products or financial transactions linked to the EU lead to deforestation, forest degradation and human rights violations. If the EU acts the UK should follow suit to curb Mr Bolsonaro’s worst environmental instincts, which are a menace to everyone on the planet.