Tokyo, 1 October 2026 – The coal that arrived at Japan’s 11 blast-furnace steel mills in 2024 carried an estimated 308 kilotonnes (kt) of methane released during mining, according to a new report by global energy think tank Ember. The figure is 4.6 times the methane Japan reports from its entire domestic energy sector, and more than double what it reports from waste. However, the methane from imported coal falls outside Japan’s inventory because it was released abroad, and outside its steelmakers’ reporting, as there is no framework that requires them to count it.
Ember’s report found that the 54.5 million tonnes (Mt) of coal received by Nippon Steel, JFE Steel and Kobe Steel carried 25 million tonnes of carbon dioxide equivalent (Mt CO2e) once weighted for methane’s near-term warming over 20 years. Nippon Steel accounts for 182 kt of that methane, from 33 Mt of coal taken in across its seven blast-furnace mills, more than the 25 Mt it discloses as coking coal. Counting it would add 46% to the Scope 3 emissions the company reports in Categories 1 and 3. On a 20-year basis, it would more than double these Scope 3 emissions.
The report highlighted that almost no accounting framework requires steelmakers to count methane emissions from the coal they purchase. Under IFRS S2 climate-related disclosure industry guidance, coal mine methane is Scope 1 for the miner and is not captured under Scope 3 for the steelmaker, so it falls between them. The Greenhouse Gas (GHG) Protocol and the steel science-based target guidance place purchased coal in Scope 3 without isolating mine methane. Only ResponsibleSteel and worldsteel’s life cycle inventory methodology require it explicitly. Further, no Japanese ministry owns the question either. The Ministry of Economy, Trade and Industry (METI) treats coal as energy security, and the environment ministry’s inventory, by international convention, stops at Japan’s border.
