What are the processes that control tropospheric pollutants?
Human activities have increased surface-level ozone concentrations and decades of research and regulations now reveal that a global approach is required to further understand the sources of ozone and other pollutant precursors. Tropospheric ozone production occurs when volatile organic compounds (VOCs) and nitrogen oxides (NO x ) are exposed to sunlight. Since the emissions of these ozone precursors are directly linked to today’s urban and industrial lifestyle, reductions are both socially and economically costly. For this reason, policymakers have sought guidance from the scientific community in determining effective ways to meet health-based ozone standards or goals. The response of ozone to changes in VOC and NOx emissions can be quite complex and variable. Moreover, winds can transport both ozone and its precursors over large distances; and, as a result, exposure to elevated ozone can arise from both local and distant sources.
