Quantifying global CH and NO footprints.

This study aims to quantify global CH and NO footprints in 2012 in terms of 181 economies and 20 world regions based on the official national emission accounts from the UNFCCC database and the global multi-region input-output accounts from the EORA database. Global total CH and NO emissions increased by 15.0% in 2012 compared to 1990, mainly driven by increasing demands of agricultural and energy products. Mainland China, Western Europe, the USA, Southeast Asia and Sub-Saharan Africa were identified as the largest five CH footprint contributors (55.6% of the global total), while Mainland China, the USA, Western Europe, Brazil and Sub-Saharan Africa as the largest NO footprint contributors (59.2% of the global total). In most developed economies, the CH and NO footprints were much higher than their emissions on the production side, but opposite picture is observed in emerging economies. 36.4% and 24.8% of the global CH and NO emissions in 2012 were associated with international trade, respectively. Substantial energy-related CH and agricultural CH and NO emissions were transferred from developed countries to developing countries. Several nations within Kyoto targets have reduced their CH and NO emissions significantly between 1990 and 2012, but the generally-believed success is challenged when viewing from the consumption side. Mainland China, Southeast Asia, Sub-Saharan Africa, Brazil, Middle East and India witnessed prominent increase of CH and NO footprints in the same period. The structure and spatial patterns of global CH and NO footprints shed light on the role of consumption-side actions and international cooperation for future non-CO GHG emission reduction.