In 2021, global air pollution reached alarming levels. IQAir found that average annual air quality in every country and 97% of cities surpassed the World Health Organization's (WHO) guidelines. The study, which analyzed data from over 6,000 cities worldwide, underscored the critical need for stricter air quality regulations.
Only 222 of the analyzed cities met WHO's air quality standards. These included the French territory of New Caledonia and U. S. territories Puerto Rico and the Virgin Islands. Meanwhile, countries like India, Pakistan, and Bangladesh reported pollution levels that were at least ten times higher than WHO recommendations.
Scandinavian countries, along with Australia, Canada, Japan, and the United Kingdom, had relatively better air quality, though they still exceeded guidelines by one to two times. The United States saw pollution levels two to three times higher than WHO standards, with Los Angeles remaining among the most polluted cities, despite a 6% improvement from 2020.
Glory Dolphin Hammes, CEO of IQAir, stressed the necessity for governments to enforce stricter national air quality standards and consider international policies for cleaner air. She highlighted that fine particulate matter, a prominent pollutant, is responsible for millions of premature deaths each year.
This assessment is the first major global analysis based on WHO's updated guidelines, revised in September 2021. The changes decreased the acceptable concentration of fine particulate matter (PM 2.5) from 10 to 5 micrograms per cubic meter. PM 2.5 is a small yet hazardous pollutant capable of penetrating lung tissue and entering the bloodstream, leading to severe health issues such as asthma and heart disease.
In the U. S., fossil fuel-powered transportation, energy production, and wildfires were identified as the primary pollution sources. The report detailed the influence of climate change-driven wildfires, including the Caldor and Dixie fires in California, which significantly escalated hazardous air pollution levels.
China, often criticized for its poor air quality, showed improvement in 2021. More than half of the Chinese cities analyzed reported lower pollution levels compared to the previous year. Beijing maintained a five-year trend of better air quality, attributed to policy-driven reductions in polluting industries.
The Amazon Rainforest, historically a crucial buffer against climate change, emitted more carbon dioxide than it absorbed last year due to deforestation and wildfires. This development threatens both the ecosystem and global air quality.
The report also highlighted disparities in air quality monitoring, particularly in developing regions in Africa, South America, and the Middle East, where data is limited. Chad appeared in the report for the first time, revealing it had the second-highest air pollution levels globally, just behind Bangladesh.
Experts such as climate change epidemiologist Tarik Benmarhnia emphasized the limitations of relying solely on monitoring stations and suggested alternative techniques for a more comprehensive understanding of global air quality.
The UN Intergovernmental Panel on Climate Change's 2021 report aligns with these findings, indicating that reducing fossil fuel use would not only slow global warming but also enhance air quality and public health. Hammes emphasized the need to shift to renewable energy to mitigate global warming, warning that failure to act could result in irreversible damage.
