Understanding Smog

Air pollution in South Asia and China reached critical levels during 2000–2023, with annual PM2.5 averaging 58.21 μg/m3, far above the 10 μg/m3 safety guideline. Peaks rose to 135.60 μg/m3, while the lowest levels stood at 12.50 μg/m3. Agriculture contributed most, with ammonia emissions averaging 456.30 kt and reaching as high as 5,812 kt. Transport demand was intense, averaging 785.45 thousand barrels per day and peaking above 8,500. Industry added steady pressure, averaging 27.18% of GDP and reaching 46.20% in some nations. Urbanization averaged 38.75% but at times exceeded 65%, with mixed effects. Renewable energy provided consistent relief, averaging 36.52% of supply and cutting PM2.5 by up to –0.72. Econometric results confirmed that agriculture, transport, and industry increased pollution, while renewables reduced it. Threshold analysis showed that risks doubled when income exceeded USD 9,000, but renewable benefits also became stronger. Long-run tests confirmed convergence, with error correction near –0.47. Policy analysis of 158 documents revealed strong negative sentiment toward burning (–0.87), urban sprawl (–0.91), and industry gaps (–0.85), while renewables (+0.82) and community adaptation (+0.65) received strong support. The evidence highlights farming and transport as the most critical threats and renewable adoption as the strongest solution for clean air and sustainable growth.