If you’re in São Paulo, you’ve surely noticed: the air quality is very poor. And it’s not just a feeling. On Monday morning (the 9th), amid heat, dry weather, and smoke from wildfires, the capital of São Paulo topped the list of cities with the worst air quality in the world, according to the Swiss website IQAir. In addition to São Paulo, the air quality technology company also identified Porto Velho (RO) and Rio Branco (AC) on Sunday as the cities with the highest pollution levels in the world.

Extreme drought and smoke from wildfires in the Amazon, the Cerrado, and the Pantanal have been polluting the air in several cities across Brazil. Cities such as Brasília, Goiânia, Uberlândia, Cuiabá, Campo Grande, and Belo Horizonte have seen the sky change color, shrouded in a haze of smoke. 

A red sky is an optical phenomenon caused by the refraction of sunlight through dust and soot. It is also a clear sign of poor air quality, which harms the climate, food production, biodiversity, and ecosystems.

In Brazil, agricultural burning and forest fires are the main source of air pollutant emissions. A study by WRI Brasil, which included experts from the International Council on Clean Transportation Brazil (ICCT Brasil) and other institutions, found that, although the country already has legislation to manage air quality and control pollution, legal certainty regarding the enforcement of these laws and the punishment of those responsible remains a major bottleneck.