Abstract:

While the period of industrious human activity is only a small fraction of the Holocene, last 12,000 years since the end of the last glacial period, considering the dramatic changes to our global environment such as decrease in stratospheric ozone and global warming, a new name,“the Anthropocene, an era of mankind”has been suggested to this period:

It is surprising that these global problems arise simply from what seem like insignificant increase in concentrations for several components of the atmosphere, concentrations for which range in only parts per million (ppmv), and some as little as parts per trillion(pptv). Two main themes standout when observing the changes in the atmospheric environment: 1) Increase in concentrations of pre-existing compounds such as CO2, CH4 and N2O and 2) Increase in concentrations of purely man-made minute compounds such as CFCs, HCFCs, and HFCs.

For man-made compounds, the Advanced Global Atmospheric Gases Experiment (AGAGE) is a successful international effort for measuring these minute components in the atmosphere since 1978. These continuous measurements allow scientists to monitor the human usage of these compounds, documenting the decrease in concentrations for CFCs coinciding with the increase in concentration for HCFCs and HFCs, helping to validate the success of international agreement such as the Montreal Protocol for protecting stratospheric ozone layer.

Atmospheric measurements can be combined with appropriate atmospheric transport models to provide scientific basis for estimating the emissions for these compounds from specific regions, allowing top-down verification of bottom-up emission inventories estimated for these compounds. This approach has been used to enhance our understanding of emission rates of many man-made compounds in East Asia, where a significant portion of the global emissions are concentrated.