GWP资料.pdfVIP

Global Warming Potentials in AR4 V. Ramaswamy NOAA/ Geophysical Fluid Dynamics Laboratory, Princeton University GWP Definition Defined as the ratio of the time-integrated radiative forcing from the instantaneous release of 1 kg of a trace substance relative to that of 1 kg of a reference gas (IPCC, 1990). A measure of the relative radiative effect of a given substance compared to another, integrated over a chosen time horizon. A simple, effective concept, in place since FAR. Representation AGWP Gas - i AGWP Ref. Gas GWP Dependencies and Complexities Radiative forcing of species: - spectroscopic details of absorption bands; - overlap of absorption features amongst species; nonlinear aspects Lifetimes of species: - uncertainties in processes and/or measurements and/or modeling; - dependence on other species e.g., chemistry; GWP Dependencies and Complexities Time horizon choice depends on the user emphasis shorter horizons if the focus is on short-term effects/ processes e.g., response of continents to a forcing shorter horizons if speed of potential climate change is of interest than eventual magnitude Longer horizons for long-term change (e.g., slow transfer of heat into the deep oceans, sea-level rise) choices used in IPCC 20, 100, 500 years GWP Considerations Reference gas CO2 - spectral absorption features well understood; - complex li