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

This study focused on 14 metal sectors of the 40 countries that are the largest CO emitters and developed a new analysis framework to estimate CO 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 CO emitter among 14 metal sectors, and their efficiency improvements can contribute to reducing CO emissions by 354 Mt, accounting for 1.4% of the global CO emissions. We further proposed efficiency improvement schemes targeting the inefficient countries in order to help those countries to effectively reduce CO emissions according to their sectoral and national characteristics.