Around 18 000 people die each day as a result of air pollution. In fact, the number of deaths attributed to air pollution each year – 6.5 million deaths – is, according to the World Health Organization much greater than the number from HIV/AIDS, tuberculosis and road injuries combined. Air pollution also brings major costs to the economy and damage to the environment. This report – released as a World Energy Outlook Special Report – examines the role of energy in air pollution. It also presents a strategy in the form of a ‘Clean Air Scenario’ in which the energy sector pushes air pollution levels into a steep decline in all countries.