Air pollution, defined as the presence of harmful substances like gases and particulate matter in the air, tragically kills 7 to 8 million people annually and significantly contributes to diseases such as stroke, heart disease, and lung cancer. Its primary sources include burning fossil fuels for electricity and transport, industrial processes, agricultural practices, wildfires, and indoor combustion of firewood for cooking and heating. Beyond human health, air pollution damages crops and forests through phenomena like acid rain, imposing a staggering economic cost of over $8 trillion per year in welfare and productivity losses globally.
To combat this, various strategies are employed, including cleaner energy sources like renewables, electric vehicles, improved waste management, and industrial scrubbers. National legislation has shown success, notably the 1956 Clean Air Act in Britain and the 1963 US Clean Air Act. While international efforts like the Montreal Protocol effectively eliminated ozone-depleting chemicals, broader global action on climate change and air quality continues to face challenges.