Impacts of productive efficiency improvement in the global metal industry on CO₂ emissions

This study focused on 14 metal sectors of the 40 countries that are the largest CO₂ emitters and developed a new analysis framework to estimate CO₂ reduction potentials based on the Greenhouse Gas Protocol through efficiency improvement of the inefficient metal sector of these countries. The analysis framework was developed by combining a multi-regional input-output database with data envelopment analysis. We found that there were 20 inefficient countries in the basic iron and steel sector, which is the largest CO₂ emitter among 14 metal sectors, and their efficiency improvements can contribute to reducing CO₂ emissions by 354 Mt, accounting for 1.4% of the global CO₂ emissions. We further proposed efficiency improvement schemes targeting the inefficient countries in order to help those countries to effectively reduce CO₂ emissions according to their sectoral and national characteristics.