| 英文摘要: | Glob. Environ. Chang. http://doi.org/brg6 (2016) Models that project how policies may impact future emissions rely on projections of how society may change in the coming decades. Over the last three years, researchers have refreshed the assumptions used to inform these models, known as the shared socio-economic pathways (SSPs), with a new set now presented in a special issue of Global Environmental Change. Keywan Riahi and colleagues from institutions across the globe present an overview of the new SSPs. The pathways are based on five narratives that seek to capture the breadth of possible development paths, factoring in differing levels of inequality, insecurity, technological progress and population growth. The narratives are then turned into quantitative projections that can be used in integrated assessment models. Unsurprisingly, there is a wide range of results depending on which SSP is used; for instance, emissions associated with the various baseline scenarios range from 25 GtCO2 per year to more than 120 GtCO2 per year by 2100. The new SSPs are now ready for use by the wider community, the authors say, with next steps including developing regional extensions and employing them with a new generation of Earth system models. |