A cross-country assessment of energy-related CO2 emissions: An extended Kaya Index Decomposition Approach

- Past and current unsustainable energy consumption patterns cannot be maintained.
- Extended-Kaya decomposition approach has been adopted in a cross-country comparison.
- Main drivers of changes in energy-related CO2 emissions have been identified.
- Energy intensity, affluence and renewable energy sources major drivers of changes.
- Need to address interconnections among carbon emissions drivers at policy level.

As the threat of climate change becomes increasingly acknowledged, it becomes more evident that past and current unsustainable energy consumption patterns cannot be pursued or maintained. In order to help policy makers across the globe to address this challenging goal, decomposition techniques have been applied to identify the main drivers of changes in energy consumption and CO2 emissions. This study presents a cross-country assessment of main energy-related CO2 emission drivers for Portugal, United Kingdom, Brazil and China, resorting to an approach that differentiates the contribution of all fuel alternatives - both renewable and non-renewable, including nuclear energy. The results obtained have shown the relevance of energy intensity and affluence effects as well as RES contribution as main emission drivers which means that their relationships constitute areas that require a more immediate action by energy policy decision-makers. In terms of policy implications, it seems clear that Brazil and Portugal need to focus on measures improving energy efficiency whereas China and UK need to prioritize issues regarding the weight of non-renewable energy sources in their energy mix. Another important implication is the need to promote synergies within the energy sector, regarding energy security, climate change and pollution mitigation goals.