Frameworks for comparing emissions associated with production, consumption, and international trade.

While the problem of climate change is being perceived as increasingly urgent, decision-makers struggle to agree on the distribution of responsibility across countries. In particular, representatives from countries hosting emissions-intensive exporting industries have argued that the importers of emissions-intensive goods should bear the responsibility, and ensuing penalties. Indeed, international trade and carbon leakage appear to play an increasingly important role in the carbon emissions debate. However, definitions of quantities describing the embodiment of carbon emissions in internationally traded products, and their measurement, have to be sufficiently robust before being able to underpin global policy. In this paper we critically examine a number of emissions accounting concepts, examine whether the ensuing carbon balances are compatible with monetary trade balances, discuss their different interpretations, and highlight implications for policy. In particular, we compare the emissions embodied in bilateral trade (EEBT) method which considers total trade flows with domestic emission intensities, with the multi-regional input-output (MRIO) method which considers trade only into final consumption with global emission intensities. If consumption-based emissions of different countries were to be compared, we would suggest an MRIO approach because of the global emissions coverage inherent in this method. If trade-adjusted emission inventories were to be compared, we would suggest an EEBT approach due to the consistency with a monetary trade balance.

Variation in trends of consumption based carbon accounts.

The UNFCCC requires the annual reporting of greenhouse gas emissions. These inventories focus on emissions within a territory, and do not capture the effect of emissions embodied in imports. Consumption based carbon accounting (CBCA) has been proposed as a complementary method to capture these emissions, and a number of global models have been developed to operationalise CBCA. However, discrepancies in country-level CBCA results occur, which can cause concern for the practical use of CBCA. Despite these quantitative difference in results, do they provide robust results when changes over time are investigated? Here we present results of all the major global models and normalise the model results by looking at changes over time relative to a common base year value. We give an analysis of the variability across the models, both before and after normalisation in order to give insights into variance at national and regional level. A dataset of harmonised results (based on means) and measures of dispersion is presented, providing a baseline dataset for CBCA validation and analysis.