Influence of recent carbon emissions on the attribution of responsibility for climate change

Abstract

International negotiations on carbon emission reduction largely depend on the attribution of historical responsibility for climate change. In recent years, carbon emissions of developing countries have clearly increased because of rapid industrialization and now exceed those of developed countries. However, recent carbon emissions (2006-2011) have not been considered in previous attribution studies. In this study, we investigate the influence of recent carbon emissions on historical responsibilities of developed and developing countries, using a fully coupled global climate-carbon model CESM (Community Earth System Model). The simulations demonstrate that developed (developing) countries contributed about 55%-62% (38%-45%) to global CO2 increase, temperature rise, upper ocean warming, and sea ice reduction by 2011. Compared with results excluding recent carbon emissions, the responsibility of developed (developing) countries is reduced (increased) by 1%-2%. These results indicate that carbon emissions in recent years have little influence on the long-term attribution of historical responsibility. Although recent carbon emissions in developing countries have grown significantly and now exceed those of developed countries, emissions and corresponding responsibility transferred from the developed to developing world through international trade have been ignored. This is a topic that requires further study.