How important is black carbon for public health and climate?

Black carbon, a component of particulate matter (PM), causes significant harm to public health (WHO, 2012) and has also been identified as a major climate forcer, ranking alongside methane and just behind carbon dioxide (Bond et al., 2013). Found almost everywhere in the atmosphere, black carbon creates warming as it absorbs sunlight. And as black carbon is emitted directly by combustion in, for example, motorized vehicles and traditional cookstoves, it also carries toxins such as polycyclic aromatic compounds.