Japan’s greenhouse gas emissions fell 1.9 per cent in 2024 to about 994 million tonnes of carbon dioxide equivalent (CO2e), dropping below the 1 billion tonne mark for the first time on record, according to the country’s environment ministry.
The total marked the lowest level since 2013 and the third straight annual decline, as the world’s fifth-largest emitter continues to edge closer to its climate targets.
Japan has pledged to cut emissions by 46 per cent from 2013 levels by 2030 and reach net zero by 2050, part of its commitments under the Paris Agreement. The latest figures represent a roughly 25 per cent reduction from 2013 levels, indicating steady — though still incomplete — progress.
The ministry attributed the latest drop mainly to lower energy use in manufacturing and continued progress in decarbonising the power sector.
Japan’s emissions trajectory has been shaped by structural shifts in its energy system since the Fukushima nuclear disaster, when most nuclear reactors were shut down and fossil fuel use surged. Emissions peaked at around 1.4 billion tonnes in 2013 before entering a gradual decline as renewables expanded and reactors restarted.
In fiscal 2024, the combined share of renewable energy and nuclear power exceeded 30 per cent of electricity generation, helping curb emissions. Renewables accounted for 23.1 per cent, while nuclear rose to 9.4 per cent, with fossil fuel-based thermal power falling to 67.5 per cent.
By sector, industrial emissions fell 2.5 per cent, while transport emissions dropped 1.6 per cent. Household emissions declined 0.7 per cent, though emissions from the commercial and services sector rose slightly by 0.2 per cent as economic activity recovered.
The ministry said improvements in the carbon intensity of electricity — emissions per unit of power consumed — contributed to reductions across industry and households.
Carbon sinks under pressure
Carbon absorption by forests and other natural sinks totalled about 52.3 million tonnes, down 9.7 per cent from a year earlier, reflecting slower growth in ageing plantations.
The decline highlights a growing structural challenge for Japan’s climate strategy: its forests, once a major carbon sink, are losing efficiency as they mature.
“Blue carbon” ecosystems such as seagrass beds and mangroves absorbed about 320,000 tonnes, a relatively small share, roughly 0.03 per cent of national emissions, but one that is drawing increasing policy attention.
Japan is exploring ways to scale up marine-based carbon removal, including seaweed cultivation projects designed to capture carbon and store it in ocean environments.
In 2025, the Hokkaido Research Organization and oil company ENEOS launched a joint survey and aquaculture test of seaweed in the waters around Hokkaido to check the creation of large-scale blue carbon.
The environment ministry said expanding carbon sinks, including forests, blue carbon and emerging technologies such as carbon capture, utilisation and storage (CCUS), would be “indispensable” to achieving net-zero emissions.
Policy, structural headwinds
Japan’s emissions decline has also been supported by cyclical factors such as reduced industrial output, raising questions about the durability of cuts as economic activity rebounds.
At the same time, the country remains heavily dependent on imported fossil fuels, exposing it to energy price shocks and complicating decarbonisation efforts.
Fluorinated gas emissions, including hydrofluorocarbons (HFCs), fell 4.8 per cent to about 32.2 million tonnes, continuing a downward trend driven by tighter regulation and a shift to lower global warming potential refrigerants.
Despite the progress, Japan’s Ministry of Economy, Trade and Industry said the country faces a narrow path to meet its 2030 target, with further reductions likely to depend on accelerating renewable deployment, nuclear restarts and scaling up carbon removal technologies.
Officials caution that sustaining emissions cuts while strengthening carbon absorption capacity will be critical as Japan balances climate goals with energy security and economic growth.
