世界气象组织：2021年世界气象组织空气质量与气候公报（英文版）

Inhaling particulate matter smaller than 2.5 micrometres (PM2.5) over long periods is a severe health hazard. Human and natural sources contribute to PM2.5 pollution in varying proportions at the global scale. Using the PM2.5 data from the Copernicus Atmosphere Monitoring Service (CAMS) re-analysis, Figure 1 shows the average PM2.5 surface concentrations for 2003–2019 and the anomalies (absolute differences) in 2020 compared with the mean values for 2003–2019. Intense wildfires generated anom