Global Threat: WMO Warns of “Vicious Cycle” Linking Air Pollution and Climate Change
A new report from the World Meteorological Organization (WMO) has issued a dire warning, stating that air pollution and climate change are locked in a “vicious cycle” that exacerbates both problems and poses significant threats to global health, economies, and ecosystems.
The WMO’s annual Air Quality and Climate Bulletin, released in conjunction with the International Day of Clean Air for Blue Skies, emphasizes that these two interconnected crises cannot be addressed in isolation and require a unified, international approach.
The report highlights that the same human activities, primarily the burning of fossil fuels, are the primary drivers of both issues. While these activities release greenhouse gases that warm the planet, they also emit harmful pollutants like black carbon, nitrogen oxides, and ground-level ozone. These pollutants not only degrade air quality, contributing to over 4.5 million premature deaths annually worldwide, but they also act as short-lived climate pollutants that further accelerate global warming. This creates a dangerous feedback loop: as the climate warms, it intensifies weather patterns such as heatwaves and droughts, which in turn fuel more frequent and intense wildfires. These fires release massive plumes of smoke and particulate matter (PM2.5) into the atmosphere, worsening air quality for millions of people, sometimes thousands of miles away.
The WMO bulletin provides a detailed look at the geographical distribution of this dual threat in 2024. While some regions, notably eastern China, have seen a decline in PM2.5 levels due to sustained mitigation efforts, others remain critical pollution hotspots. Northern India, in particular, is highlighted as a region with persistently high pollution. The report also underscores the significant impact of wildfires in regions like Canada, Siberia, central Africa, and the Amazon basin, where fire-driven PM2.5 levels were well above average. The Amazon basin, in particular, experienced record wildfires fueled by drought, leading to a substantial increase in air pollution.
A particularly complex aspect of this relationship is the role of aerosols, tiny airborne particles that can either cool or warm the atmosphere. While some aerosols, like sulphates from industrial emissions, have a temporary cooling effect by reflecting sunlight back into space, others, such as black and brown carbon, absorb sunlight and warm the atmosphere. The report notes a complex, and in some cases, paradoxical effect of clean-air policies. For example, while international regulations on shipping have successfully cut sulphur emissions, saving lives and reducing respiratory diseases, the consequent reduction of sulphate aerosols has slightly accelerated global warming by removing a portion of their cooling effect. This underscores the need for a comprehensive strategy that tackles greenhouse gases and air pollutants in tandem.
The findings from the WMO are consistent with research from other organizations, including the Environmental Defense Fund (EDF) and the National Centre for Atmospheric Science (NCAS). The NCAS, in a recent study, found that the significant reduction of air pollution in East Asia since 2010 has inadvertently contributed to a measurable acceleration in global warming, accounting for an additional 0.07°C of warming. This phenomenon, while a testament to the success of public health efforts, reinforces the WMO’s central message: addressing one problem without the other is a partial solution at best. Experts from these organizations and others, including the UN Environment Programme, stress that integrated policies promoting renewable energy, green public transport, and cleaner industrial processes are the most effective way to achieve a “win-win” outcome for both human health and the climate.
