Eight miles of Amazon rainforest will be cleared to make way for a road in the city hosting this year’s United Nations climate summit, Cop30.

The creation of a four-lane highway near Belem in northern Brazil has alarmed residents and conservationists, who said it is damaging livelihoods and will create a fragmented forest and deadly obstacle for wildlife.

The state government of Para had floated the prospect of the Avenida Liberdade since 2012, but it was delayed for years by environmental concerns. The road was included in a 2020 plan before Brazil confirmed in 2023 that it wanted to host Cop (the Conference of the Parties) in Belem.

Construction work began on the highway, which is designed to reduce congestion and accidents on other roads, in June last year. The development is one of several infrastructure projects under way in and around Belam as the authorities rush to prepare the port city for tens of thousands of delegates arriving in November.

President Silva has forged partnerships on climate change with the UK before the conference, which is designed to act as a deadline for nations to submit plans for cutting greenhouse gas emissions by 2035. The Amazon rainforest is a significant sink for carbon emissions.

Hosting Cop30 has put a spotlight on Belem, the capital of Para, which is often described as a gateway to the Amazon river and rainforest. The partially built road has upset people who live near it and relied on food produced from the trees for their income. “Our harvest has already been cut down. We no longer have that income to support our family,” Claudio Verequete, who lives about 200 metres from the road and harvests berries from trees, told the BBC.

New highways in the world’s greatest rainforest often have a so-called fishbone effect, where they create access for authorities and businesses to build new roads running perpendicular from the original one, leading to even greater deforestation. “Our fear is that one day someone will come here and say: ‘Here’s some money. We need this area to build a gas station, or to build a warehouse.’ And then we’ll have to leave,” Verequete said.

Researchers have warned that the road will divide the Belem environmental protection area and the Utinga state park, fragmenting a biodiversity hotspot; the two areas have more than 800 species of plants and fungi.

Local authorities have presented the road as “sustainable”, pointing to cycle lanes, lighting provided by solar energy and several dozen wildlife crossings and noise barriers.

Belem’s airport is being expanded, hotels are being built and cruise ships are being considered as a way to provide extra accommodation. A disused runway is being turned into a park and buildings to host the summit; Azerbaijan held last year’s Cop in the Olympic stadium in Baku.

This week the Brazilian diplomat charged with hosting the talks, the Cop30 president designate Andre Aranha Correa do Lago, called for countries to unite by drawing inspiration from how countries left their differences behind after the Second World War.

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“This year marks the 80th anniversary of the end of [the war] and of our alliance in creating the United Nations. German-American philosopher Hannah Arendt denounced the ‘banality of evil’ as the acceptance of what was unacceptable. Now, we face the ‘banality of inaction’, an irresponsible and unacceptable inaction,” Lago said, referring to a lack of action on emissions, which led to record global warming last year.