Air Quality Life Index, June 2022 Annual Update By Michael Greenstone, Christa Hasenkopf and Ken Lee: “During the first year of the Covid-19 pandemic, the world’s economy slowed. Yet, the global annual average particulate pollution (PM2.5) was largely unchanged from 2019 levels. At the same time, growing evidence shows air pollution—even when experienced at very low levels—hurts human health. This recently led the World Health Organization (WHO) to revise its guideline (from 10 µg/m³ to 5 µg/m³) for what it considers a safe level of exposure of particulate pollution, bringing most of the world—97.3 percent of the global population—into the unsafe zone. The AQLI finds that particulate air pollution takes 2.2 years off global average life expectancy, or a combined 17 billion life-years, relative to a world that met the WHO guideline (5 µg/m³). This impact on life expectancy is comparable to that of smoking, more than three times that of alcohol use and unsafe water, six times that of HIV/AIDS, and 89 times that of conflict and terrorism. “It would be a global emergency if Martians came to Earth and sprayed a substance that caused the average person on the planet to lose more than 2 years of life expectancy. This is similar to the situation that prevails in many parts of the world, except we are spraying the substance, not some invaders from outer space,” says Michael Greenstone, the Milton Friedman Distinguished Service Professor in Economics and creator of the AQLI along with colleagues at the Energy Policy Institute at the University of Chicago (EPIC). “Fortunately, history teaches us that it does not need to be this way. In many places around the planet, like the United States, strong policies, supported by an equally strong willingness for change, have succeeded in reducing air pollution.”