Global Health Imperiled: Air Pollution Rises, Climate Warms, But Hope Emerges from Concerted Action

As billions worldwide continue to breathe polluted air, leading to more than 4.5 million premature deaths every year, UN climate experts have issued a stark warning about the damaging impact of microscopic smoke particles from wildfires, which can travel halfway across the globe. This grim reality is intertwined with the relentless rise in global temperatures, a phenomenon observed since the Industrial Revolution and largely attributed to human activities, particularly the emission of heat-trapping greenhouse gases.

The World Meteorological Organization (WMO) highlighted that "Air quality respects no boundaries," with smoke and pollution from wildfires detected far from their origin points. The latest WMO Air Quality and Climate Bulletin reveals a persistent pattern of pollution "degradation" globally, with telltale fine particle markers (PM 2.5) from wildfires concentrated in regions such as Chile, Brazil, Ecuador, Canada, central Africa, and Siberia. This trend aligns with the observation that wildfire seasons are becoming "stronger and longer every year" as a direct consequence of climate change.

Adding to the complexity, while main pollutants like sulphur dioxide (SO₂) and nitrogen oxide (NOₓ) are decreasing due to emission controls, ground-level ozone levels – a primary component of smog – have not declined. This is partly a result of global warming, as ozone forms through chemical reactions in the atmosphere that necessitate sunlight. WMO Deputy Secretary-General Ko Barrett underscored the critical message: "Climate change and air quality cannot be addressed in isolation. They go hand-in-hand and must be tackled together".

The connection between air quality and climate change is undeniable. Since 1880, the average global temperature on Earth has increased by at least 1.1° Celsius (1.9° Fahrenheit), with the majority of this warming occurring since 1975 at a rate of roughly 0.15 to 0.20°C per decade. The past nine years, up to 2022, have been recorded as the warmest since modern recordkeeping began. This global warming is not uniform; temperatures might rise significantly in one area while dropping elsewhere, and warming is generally greater over land than over oceans. A one-degree global change is profoundly significant, requiring a vast amount of heat to warm the Earth's oceans, atmosphere, and landmasses. Historically, a mere one-to-two-degree drop was enough to usher in the Little Ice Age.

Despite these alarming trends, there are signs of progress. The WMO scientist Lorenzo Labrador specifically pointed to a reduction in emissions in some parts of the world, "particularly eastern China and Europe, year on year". This demonstrates that "When we see that countries or regions or cities are taking measures to fight against bad air quality, it works". Shanghai, China, serves as a good example, where improvements have been made through initiatives like opening more parks, planting more trees, and the increasing use of electric vehicles.

However, even with these successes, very few cities globally meet the air quality levels recommended by the UN World Health Organization (WHO), indicating that air quality remains a significant public health concern. Efforts are also underway to tackle household air pollution, a major public health threat, especially for children. The good news is that "cleaner cooking technology is plentiful, relatively inexpensive, and already helping to save lives," though the challenge remains to make this technology accessible to more people.

At an intergovernmental level, the Convention on Long Range Transboundary Air Pollution (often called the Air Convention) has been instrumental in improving air quality across the pan-European region and North America since its adoption in 1979. This international agreement, supported by the UN Economic Commission for Europe (UNECE) and involving 51 countries, sets legally binding emissions limits for major air pollutants. UNECE states that the Convention has saved an estimated 600,000 lives annually and added a whole year to life expectancy in Europe. Other regions, particularly in East and South Asia and South America, are now looking to adopt the successful science-policy model of the Air Convention. UNECE also plays a crucial role in establishing international norms for vehicle emissions measurement methods and cleaner fuels.

The evidence from NASA's Goddard Institute for Space Studies (GISS), which incorporates surface temperature measurements from over 20,000 weather stations and other observations, consistently shows rapid warming in recent decades, with the last decade being the warmest. This underscores the critical need for continued and expanded efforts. As the world navigates the twin crises of rising air pollution and global warming, these integrated solutions offer a path towards protecting the health of our planet, communities, and economies.