Black carbon soot, ground-level (tropospheric) ozone, methane, and hydrofluorocarbons (HFCs) are collectively known as short-lived climate pollutants. They remain in the atmosphere for days to a few decades, and are responsible for up to half of global climate change and the associated adverse impacts. They can be cut quickly using existing technologies and often using current laws and institutions. Reducing them can cut the rate of global warming in half and the rate of warming in the Arctic by two-thirds. The Arctic is currently warming at twice the rate of the global average, and Arctic melting is predicted to contribute to sea level rise of as much as 5 feet by the end of the century, according to the International Arctic Monitoring and Assessment Program. This is more than two and a half times higher than the sea level rise projected in 2007 by the Intergovernmental Panel on Climate Change.
In addition to causing up to half of global climate change, these short-lived climate pollutants are causing serious harm to public health. Black carbon soot kills as many as 2.4 million people each year, mostly women and children. Ground-level ozone also causes other debilitating health effects, as well as significant damage to food crops. Protecting vulnerable people and places from increasing climate impacts requires fast mitigation of short-lived climate pollutants.