State of Global Air
Also called: SoGA · Topic: Geographical Issues: Pollution, Urban Waste, Slums and Land Degradation · NCERT: Beyond NCERT
Meaning
State of Global Air (SoGA) is a report on how dirty the air is around the world and how much harm it does to health. It is prepared by the Health Effects Institute, a research body in the United States, with partner organisations. It brings together data on pollutants such as particulate matter (tiny bits of dust and smoke in the air) and household smoke. It then estimates how many people in each country die early because of them. It matters because it turns pollution levels into a health cost. This makes it a common source for numbers on India's air pollution burden.
Example
The State of Global Air 2025 report put air pollution behind more than 20 lakh deaths in India in 2023. These deaths came mostly from the Indo-Gangetic plain, including Delhi. In Delhi, the November–January winter smog builds up when temperature inversion (cold air trapped near the ground under warmer air) and calm winds hold pollution over the city.
Don't confuse with
- Environmental Performance Index: published by Yale and Columbia Universities. It ranks countries on their overall environmental performance (India was 176 of 177 in 2026). It does not count deaths from air pollution.
- National Air Quality Index: India's daily scale, launched in 2015. It combines eight pollutants into one number for a city's air on a given day. It is not a global report on health impact.