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How is surface-level ozone connected to air pollution and global warming?

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Grinnell Glacier shrinkage — Global warming A series of photographs of the Grinnell Glacier taken from the summit of Mount Gould in Glacier National Park, Montana, in (from left) 1938, 1981, 1998, and 2006. In 1938 the Grinnell Glacier filled the entire area at the bottom of the image. By 2006 it had largely disappeared from this view.

Surface-level ozone ( $O_{3}$ ) is a significant greenhouse gas that contributes to global warming by absorbing heat energy emitted from Earth's surface and reradiating it back toward the ground.12

Its connection to air pollution is direct: unlike stratospheric ozone, which occurs naturally and protects life from ultraviolet radiation, surface-level ozone is primarily an anthropogenic pollutant. It is formed through photochemical reactions in the lower atmosphere involving pollutants such as carbon monoxide, nitrogen oxides, and volatile organic compounds, often in the presence of strong sunlight and hot weather.1345

These conditions frequently lead to the formation of photochemical smog in urban areas, where ozone concentrations can reach unhealthy levels. Because it acts as a greenhouse gas with a net radiative forcing of approximately 0.35 watt per square metre, surface-level ozone plays a measurable role in the Earth's radiation balance and the broader process of global warming.13