The Amazon is suffocating thanks to the BR-319 highway

In October 2023, Manaus vanished behind a suffocating wall of smoke. The capital of Amazonas woke up to one of the worst air pollution crises the Amazon has ever seen.

The sky turned the colour of ash, more like a dystopian film set than the world’s largest tropical forest. The air grew so heavy and toxic that residents dug out their old covid masks just to breathe.

For weeks, the population of Manaus, over two million people, endured a suffocating haze, with pollution so severe it matched, and at times exceeded, the levels of the world’s dirtiest megacities.

The Amazon’s BR-319 smoke pollution crisis: a health emergency

The Amazon has always swung between wet and dry seasons, but in 2023, things aligned in the worst possible way. An El Niño in the Pacific collided with an Atlantic dipole, a pattern of warmer water in the north Atlantic and cooler water in the south. The result was a brutal drought priming the forest to burn.

Burning forests release smoke filled with microscopic particles (PM2.5), which act strangely in the atmosphere: instead of forming raindrops large enough to fall, they create tiny droplets that just hang there. In other words, smoke keeps rain from falling, drought drags on, and more fires ignite.

According to a recently-published study in the Discover Sustainability journal, on 12 October 2023, air quality monitors in Manaus registered PM2.5 levels of 314 micrograms a cubic metre (µg/m3), more than twenty times the World Health Organization’s safety limit.

To put it into perspective, that number beat even Delhi’s infamous pollution peaks that year. For a city like Manaus, accustomed to relatively clean air, it was like being plunged into a health emergency overnight.

The smoke crisis in Manaus happened under president Luiz Inácio Lula da Silva’s government.

An enormous health hazard

We often think of water and food as our most basic needs, but we take in far more air every day, about 14 kilograms of it, compared to just 2 kilograms of water and 1.5 kilograms of food. Every breath in Manaus during the crisis was filled with toxins.

The dangers of prolonged exposure to polluted air the population of Manaus were under, can cut months, even years, off life expectancy. Doctors have long warned that breathing PM2.5 damages the lungs, strains the heart, and weakens the immune systems.

In the Amazon, the crisis landed hardest on children, older people, and people already living with fragile health. What should have been a season of heat and river breezes, turned into weeks of coughing, burning eyes, and the smell of ash.

Who lit the match?

At first, state officials, including the governor of Amazonas, Wilson Lima, and the state’s secretary of the environment, were quick to blame the neighbouring state of Pará as the source of fires. However, the study and its data tell a different story.

The study revealed that satellite imagery, air quality sensors, and field inspections identified the southern area of Manaus, particularly the municipalities of Autazes, Careiro, and Manaquiri, located along the BR-319 and AM-254 highways, as the main sources of smoke emissions.

Vast areas of forest weren’t lost to accident; they were burned on purpose to make way for cattle pasture. After the fires, bulldozers moved in, water buffalo spread across the fresh clearings, and illegal side roads crept further into once-intact rainforest.

The lead author of the study, Lucas Ferrante, a researcher at the University of São Paulo (USP) and the Federal University of Amazonas (UFAM), mentioned:

This study shows that Brazil is heading in the opposite direction of its commitments for COP30, with millions of tons of emissions turning Manaus into a city under smoke. The forest is burning while public officials such as the governor of Amazonas, Wilson Lima, deflect attention away from the fires, even as they endorse laws that benefit those who use fire to clear land and illegally expand cattle ranching.

Fires weren’t just an unfortunate by-product of drought; they were tools in a land-grabbing playbook.

BR-319: the road that lights the fire

At the heart of the crisis lies the BR-319 highway, linking the capital of Amazonas, Manaus, to the capital of Rondônia, Porto Velho.

First built in the 1970’s, abandoned in the 1980’s, the road is now at the heart of a heated debate: should it be rebuilt and paved?

Supporters call the reconstruction of the BR-319 highway ‘development’, but critics call it destruction.

Studies show that deforestation rates within 40km of the BR-319 are already more than double the Amazon average. The mere promise of reconstruction of the highway has triggered waves of illegal occupation.

If fully rebuilt, the BR-319 would connect Manaus, still surrounded by vast intact forest, to the “arc of deforestation” further south, dragging the chaos of frontier expansion straight to the heart of the central Amazon.

Supporters argue that paving the road is about development and connection, but the evidence suggests otherwise. More roads mean more illegal side roads, more land grabbing, more illicit activities, more fire, and more smoke choking cities like Manaus.

Ferrante highlighted the lack of coordination and accountability among different levels of government in addressing the issue. He stressed that the situation reveals deep contradictions in Brazil’s leadership on climate and infrastructure:

There is no effective command or control, and negligence is evident across municipal, state, and federal authorities. Right now, President Lula is paving ‘Lot C’ – a 52-kilometer section of the BR-319 highway – without environmental studies or licensing, a contradictory move for someone who presents himself as a climate leader.

The 2023 smoke crisis wasn’t an isolated event; it was a warning of what’s to come if this road is allowed to go ahead.

A governance failure

Beyond the weather patterns and the bulldozers, what really fuelled the smoke crisis was weak governance.

State and federal authorities failed to act quickly and effectively. Requests for federal help came late, long after the skies had turned toxic. Local agencies looked the other way and cattle ranchers carved up Indigenous lands.

Instead of tackling the root cause, some leaders doubled-down on roadbuilding and laws that make it easier to legalise deforestation after the fact.

For the people of Manaus, this went beyond politics, it was personal, a reminder that failures in policy ultimately reach the the very air they breathe.

It’s easy to view Manaus’ smoke crisis as a purely local issue, but the Amazon is interconnected, and its problems resonate far beyond one city.

The forest generates moisture that flow south, the so called ‘flying rivers‘, feeding crops, rivers, and water reservoirs across Brazil and beyond. Its role in stabilising climate is critical.

Burning and replacing the forest with pasture in the BR-319 region threatens all of that, risking tipping the central and western Amazon toward ecological collapse, accelerating biodiversity loss already driven by the climate crisis. It also compromises the water and climate systems that millions of Brazilians, and the world, rely on.

A shift in mindset is required, away from the idea that roads equal progress, and toward a vision where the Amazon’s values lie in its standing forest, flowing rivers, and thriving communities.

A warning of what’s to come

The 2023 smoke crisis was a warning, an unforgettable sign of what happens when climate extremes, fire, and governance failures collide.

It showed that the reconstruction of the BR-319 highway isn’t just an infrastructure project, it’s an environmental gamble with stakes that include public health, biodiversity, and climate stability.

The people of Manaus, who lived under toxic skies, deserve better leadership and policies that protect their air, their health, and their future.

The Amazon is often called the lungs of the planet. But in 2023, those lungs wheezed. The question now is whether Brazil, and the world, will take the warning seriously, or whether we’ll allow the next crisis to arrive, heavier, darker, and harder to breathe through.

Feature image via Channel 4 News/Youtube.