How polluted cities became examples of environmental recovery

In some parts of the world, including Brazil, cities faced with high levels of pollution have been able to turn around by adopting cleaner urban models.

Bogotá, Colombia, is a reference in sustainable mobility using electric buses and promoting bicycle paths. In Brazil, Curitiba has invested in more efficient public transport and recycling policies. The city is also known for having 70% of the population using public transportation, a model that has helped maintain low levels of polluting gas emissions.

Freiburg in Germany has adopted “passive” buildings, which significantly reduce energy consumption, and Copenhagen in Denmark has reduced emissions by investing in bicycle paths and integrated transportation.

Clean mobility in major cities

For this change to actually happen, it is necessary for cities to provide adequate infrastructure, such as safe and shaded roads for the use of bicycles and scooters, making travel without a car more attractive. High-quality public transportation completes the cycle, allowing residents to replace cars with collective or alternative means.

Reducing pollution in cities, according to Flavia Martinelli, a climate change specialist at WWF Brazil, depends on political decisions that work together.

“To reduce pollution in cities, a set of public policies is needed,” says Flavia. “There is no point in encouraging the use of bicycles if there are no safe bicycle paths or efficient public transport. Actions must be integrated into urban reality.”

Waste management and recovered rivers

Waste management and wastewater treatment are also key pillars in cities that have successfully reversed pollution. Since the implementation of the National Solid Waste Policy, Brazilian municipalities have established recycling programs, methane recovery plants, and public-private partnerships to properly dispose of waste.

Smart drainage solutions such as modern urban engineering strategies that mimic the natural behavior of water in landscapes are also becoming a reality. Some cities dug rivers and built linear parks that served as detention basins. In addition to reducing flooding, these measures improve water quality and restore streams to the urban landscape.

Urban growth with more green spaces and less traffic

After investing in mobility and waste management, many cities have increased their interest in the way they occupy their land. Green areas, tree-lined streets and accessible squares help improve air quality and lower temperatures in densely populated areas.

“Nature-based solutions have proven particularly effective because they act as living filters, stabilizing the microclimate in urban areas and helping to continuously reduce the concentration of pollutants,” says Ana Carolina Nadalini, environmental engineer and professor at the Brazilian Institute of Assessments and Engineering Expertise (IBAPE).

Another strategy was to create service and trade centres. Instead of concentrating everything in the centre, decentralization reduces the need for long journeys. The strategy facilitates traffic and reduces gas emissions from cars.

Cities that invest in green areas and decentralize trade are able to reduce travel and reduce polluting emissions. Picture of Curitiba, Paraná.

Education and public policy must go together

Samantha Pineda, a lawyer and legal advisor to the Front Parliamentary Agricultural Front (FPA), says residents’ participation is crucial for the changes adopted by cities to be effective.

“No environmental policy can survive without community participation. Laws are important, but people’s participation is what guarantees real results,” explains Samanta.

Environmental education campaigns, efficient garbage collection, and well-organized public services contribute to promoting adherence to these sustainable practices.

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