Climatic effects due to increasing atmospheric trace gases and their induced ozone changes

Abstract

Observations have shown that concentrations of atmospheric trace gases CO2, CH4, N2O, and CFCs are increasing and the trend of increases will most likely continue (Table 1). Increases of these radiatively and chemically important trace gases may have implications for global climate both directly by perturbing the thermal radiation (the greenhouse effect; Table 2) and indirectly by changing atmospheric ozone distribution (Wang et al, 1986; Ramanathan et al, 1987; Ramanathan, 1988; UNEP, 1989). In recent years concerns have been raised about whether the observed increase in global surface temperature of 0.5°C in the last hundred years is related to the greenhouse effect (WMO/UNEP, 1990). These concerns intensified after the 1988 abnormal weather of record high temperature and drought conditions in many regions of the United States and record storms sweeping over Europe. These weather anomalies are not inconsistent with the simulations from the General Circulation Models (GCMs), which predict a substantial global warming in the next few decades. To address this future global warming potential, the Intergovernment Panel on Climate Change (IPCC) organized by the United Nation Environmental Programme (UNEP) started early 1989 to prepare a report documenting the current scientific understanding of the greenhouse effect, its potential effect and impact, and the strategy to stabilize the emissions of these greenhouse gases (WMO/UNEP, 1990).