It translates smog into lost years — and China’s cleanup into years regained.
The Air Quality Life Index, maintained by the Energy Policy Institute at the University of Chicago (EPIC), takes the abstract question of air pollution and answers it in the unit people actually feel: years of life. For environmental governance coverage, the AQLI supplies the flagship quantitative framing of China’s “war on pollution” — and the clearest illustration of both what the data can say and what it cannot.
The idea
The AQLI starts from a causal question: how much life does a given level of fine-particulate (PM2.5) exposure take away? Its life-expectancy conversion is rooted in two peer-reviewed studies by Michael Greenstone and co-authors, built on a natural experiment along China’s Huai River — winter heating was provided free north of the river but not south, creating a sharp exposure boundary that the researchers exploited with a regression-discontinuity design (Chen et al., 2013; Ebenstein et al., 2017). The official methodology note puts the result this way: sustained exposure to an additional 10 µg/m³ of PM10 reduces life expectancy by 0.64 years, translating to 0.98 years per 10 µg/m³ of PM2.5.
That coefficient is then applied to satellite-derived PM2.5 maps (sea salt and mineral dust removed, sourced from the Atmospheric Composition Analysis Group at Washington University in St. Louis), population-weighted with LandScan data, at global and subnational granularity. Users can see what a place would gain if PM2.5 fell permanently to the WHO annual guideline (5 µg/m³), to a national standard, or to a level they choose.
The China numbers
The 2025 annual report edition (“Is China Winning its War on Pollution?”, China Fact Sheet 2025, based on 2023 annual PM2.5 data — the latest edition available) evaluates trends from 2014 to 2023 against a 1998 baseline. Its China figures:
- PM2.5 down 40.8% between 2014 and 2023
- If reductions persist, that adds roughly 1.8 years of life expectancy
- Even so, China’s pollution remains about 5.5 times the WHO guideline, cutting lives short by roughly 2.2 years
These are conditional projections — years that would be gained provided the reductions are sustained — not measured health outcomes. Treat them as such in any quotation.
What the index is not
The AQLI’s own documentation draws the boundary sharply, and this page holds it: the index is a health-damage translation, not a policy prescription. Its estimates describe the long-term consequences of annual PM2.5 exposure — not real-time air quality, not short-term exposure risk, and not a substitute for regulatory ground-monitoring networks. It does not measure indoor air pollution, the economic costs of pollution, or non-particulate health effects. And it does not establish that any particular policy caused the observed pollution declines; that causal question belongs to separate policy research.
Methodological caveats
- A single causal coefficient, derived from one Chinese quasi-experiment (a specific population, pollution mix, and period), is applied across countries, pollution sources, and demographics. That transportability is an assumption built into the index, not a property the data verifies.
- Satellite-derived PM2.5 estimates carry retrieval error, especially in remote or poorly monitored regions; they complement rather than replace ground monitoring.
- An attributed scholarly caution: the index should not be overrelied upon for policy evaluation without regional and urban–rural wealth controls, since life-expectancy gains correlate with development levels that pollution reductions do not themselves cause.
Practical details
- Producer: Energy Policy Institute at the University of Chicago (EPIC) — institution profile in this directory
- Currency: annual editions; 2025 report edition latest available; open data repository (GitHub: aqli-epic/aqli-update)
- Coverage: global; satellite-derived annual PM2.5 from 1998 to 2023; unit of observation is the geographic grid cell, country, or subnational region; reported metric is potential gain in life expectancy (years)
- Access: open — interactive dashboard at aqli.epic.uchicago.edu; annual report and fact-sheet downloads; open data repository on GitHub
- Citation form: Air Quality Life Index, 2025 Report, EPIC, University of Chicago. Methodology papers: Chen, Y., Ebenstein, A., Greenstone, M., & Li, H. (2013); Ebenstein, A., Fan, M., Greenstone, M., He, G., & Zhou, M. (2017).