Pressure indicators

ODS consumption

The main cause of stratospheric ozone depletion is ODS emissions derived from the consumption of these substances (WMO et al., 2007; NASA, 2009). Since consumption is the sum of ODS produced plus ODS imported minus ODS exported (Semarnat, 2009), this indicator turns out to encompass most of the information on the process and fate of the different ODS. The impact of ODS depends on both their quantity and their ozone-destroying potential, which is known as ozone-depletion potential (WMO et al., 2007). For this reason, ODS consumption is weighted according to this potential. The indicator Global weighted consumption of ozone-depleting substances shows the magnitude of the pressure globally imposed on the ozone layer, while the National weighted consumption of ozone-depleting substances reveals the pressure at the country level. The United Nations, OECD and the indicators of the Millennium Development Goals include an indicator on ODS weighted consumption (UN, 2001 and 2008; OECD, 2005).