This country note features selected environmental indicators from the OECD Core Set, building on harmonised datasets available on OECD Data Explorer. The indicators reflect major environmental issues, including climate, air quality, freshwater resources, waste and the circular economy, and biodiversity. Differences with national data sources can occur due to delays in data treatment and publication, or due to different national definitions and measurement methods. The OECD is working with countries and other international organisations to further improve the indicators and the underlying data. The text of this country profile is complementary to and has benefited from the OECD Environmental Performance Review of Japan 2025.
Environment at a Glance: Japan
Japan is one of the largest economy in the world and one of the most densely populated countries. It is an archipelago of over 14 000 islands. The four main islands (Honshu, Hokkaido, Kyushu and Shikoku) represent 98% of Japan’s total area, totalling some 378 000 km2. Japan industries are globally recognised for their high-quality products and technological advances. The country is one of the largest merchandise exporters, with particularly strong performance in vehicles, machines and electronic equipment. Population and economic activities are extremely concentrated in dense metropolitan areas and along coastal plains, while two-thirds of the archipelago is mountainous and covered with forests. Japan has the 3rd largest forest area in the OECD after Finland and Sweden.
Japan’s large range of latitude results in a wide diversity of flora. Vegetation ranges from subtropical to temperate and cold temperate, and even alpine. Natural forests make up about half of the total area. Complex coastlines with many bays and small islands provide Japan with an abundance of marine life. Japan is relatively poorly endowed in natural resources. It has enough resources in magnesium, gold and silver to meet its needs, but has to import a wide variety of minerals. Japan is also a very large importer of wood and wood products, as well as of living marine resources, which constitute a large share of the Japanese diet. For its energy supply, the country is heavily reliant on imported fossil fuels, in particular since the 2011 Fukushima accident, which led to a total suspension of the nuclear power fleet (which has only partially restarted).
Japan has achieved decoupling between real GDP growth, energy and production-based CO2 emissions since the mid-2000s. Still, Japan is among the largest emitter of GHG emissions in the OECD and worldwide.
The per person production-based and demand-based (or footprint) greenhouse gas (GHG) emissions have started to decline since 2013. They are below the OECD averages. Demand-based emissions are higher than production-based ones, meaning that Japan is a net importer of GHG emissions embodied in its final demand.
Energy industries are the largest source of greenhouse gas (GHG) emissions, followed by the industrial sector and transport. Despite a large forest area, the land use, land-use change and forestry (LULUCF) sector provides a modest carbon sink with respect to total emissions.
Japan has negligible fossil-energy resources and relies almost entirely on imported fuels. Japan is the fifth-largest oil consumer in the world the third-largest net importer of crude oil, and the largest net importer of liquefied natural gas (OECD, 2025[1]). Its energy mix is therefore dominated by fossil fuels, 85% of total energy supply in 2023.
Japan has diversified its energy mix through the gradual expansion of renewable energy and the restart of some nuclear power plants. Renewables provided 23% of electricity in 2023. This, along with energy efficiency improvements, has helped reducing Japan’s GHG emissions since 2013 (IEA, 2021[2]).
Air emissions have been steadily decreasing since 2000, with sulfur oxide (SOx), nitrogen oxide (NOx) and non-methane volatile organic compounds (NMVOC) dropping by about half. As a result, emission intensities, both per person and per GDP, are well below the OECD average.
Population exposure to PM2.5 is still well above the 2021 World Health Organisation threshold of 5 microgrammes/m3. There are also important regional differences, from 10 µg/m3 in Tohoku to 14 µg/m3 in Okinawa.
Japan is not a water-rich country and is under moderate water-stress, with gross freshwater abstractions representing 19% of total renewable resources. On the other hand, gross freshwater abstractions per person remain below the OECD average.
81% of population are connected to wastewater treatment plants, but only 37% are connected to advanced, tertiary treatment.
Japan has made good progress in per person municipal waste generation. With 326 kg/person/year in 2021, Japan is well below the OECD average, and the amount has been steadily decreasing since 2000. Waste treatment modes have not evolved much since 2000, incineration with energy recovery being the main treatment mode.
Per person domestic material consumption is low by OECD standards, but has stagnated since 2000 and material footprint is much higher. On the other hand, Japan is among the most resource efficient country, with a material productivity far above the OECD average.
Japan has rich biota. The number of known species is estimated to be over 90 000, and to exceed 300 000 if unclassified species are included. It also has a high rate of endemic species. The surrounding seas also have a rich diversity of species, containing 50 of the world’s 127 marine mammals, 122 of the world’s 300 sea birds and 3 700 marine fish species. According to a recently developed vegetation map, forests account for 67% of the total land area, including 17.9% of natural forests. Much of the natural vegetation (consisting of natural forests and natural grassland), which currently accounts for nearly 20% of Japan’s total land area, is distributed in the natural mountain area.
In addition to its four main islands, Japan has over 14 000 islands. These unique ecosystems possess distinctive biota and are highly vulnerable, being affected by the destruction of habitats and introduction of invasive species.
The main threats generated by human activities and development include illegal digging, overexploitation of resources for ornamental or commercial uses, destruction or deterioration of habitats due to land reclamation/development in coastal areas, and changes in land use (CBD, 2022[3]).
Japan’s official national records show a terrestrial coverage of protected areas of 20.8% and a marine coverage of 13.3% in 2024. Both are below the 2030 GBF target (under the Convention on Biological Diversity) to protect at least 30% of land area, coastal and marine areas.
This section shows selected policy instruments based on data available for most OECD countries and does not provide a complete overview of countries’ policy mix to achieve their environment-related objectives. Interpretation should consider the country specific context.
The share of environmentally-related tax revenue in GDP has been declining since 2010 and is below the OECD average. Its share in total revenues has also declined and is now below 4%, energy and transport based, with limited taxes on pollution or on resource use.
Besides scientific research, the government provides direct and indirect funding in support of Japanese companies participating in fossil-fuel exploration projects overseas particularly with natural gas, a fuel whose role has increasingly grown following the 2011 Fukushima nuclear accident. Furthermore, since 2011, the government has provided financing for investments aimed at increasing the efficiency of the oil refining and distribution segments. For these reasons, almost the entirety of Japan’s support benefits the oil and gas production sector, mostly aimed on research and development funding for fossil-fuel exploration projects destined overseas. In 2022, to mitigate energy prices resulting from the global energy crisis the government introduced new measures, namely subsidies to mitigate fuel, gas, and electricity prices (OECD, 2023[4]).
In total, 63.9% of GHG emissions in Japan were subject to a positive Net Effective Carbon Rate (ECR) in 2023. Explicit carbon prices in Japan consist of emissions trading systems (ETS) permit prices and carbon taxes, which cover 70.2% of greenhouse gas (GHG) emissions in CO2 eq. With roughly 70% of total GHG emissions, coverage is largest for carbon taxes. Fuel excise taxes, an implicit form of carbon pricing, cover 73.1% of emissions in 2023. Direct fossil fuel subsidies cover 11.3% of emissions. About 8% of GHG emissions have a Net ECR above EUR 60 per tonne of CO2 eq., a mid-range estimate of current carbon costs. Net ECRs are highest in the road transport sector, which accounts for 14.1% of the country's total GHG emissions. The Net ECR is zero or negative in the agriculture & fisheries, off-road transport, buildings, industry and other GHG emissions sectors. Together, these sectors account for 50.4% of GHG emissions (OECD, 2024[5]).
Japan is amongst the world leaders in energy research and development, with direct public spending on energy research as a percentage of its GDP being one of the largest amongst OECD countries. Recent boosts in research funding were seen after the 2011 Great East Japan Earthquake, particularly on developing technologies relating to the extraction of natural gas from frozen methane hydrate in Japan’s Nankai Trough (OECD, 2023[4]).
Japan is also a major player in environmentally-related inventions, with one of the highest number of per capita inventions by residents in the OECD area. The share of environmentally-related in total inventions follows closely the OECD average, at 9% in 2022.
Japan focuses on quality growth, poverty eradication, peace and stability, and global challenges, leveraging its expertise while respecting partner countries’ ownership. Japan provides more than half of its official development assistance (ODA) in the form of non-grants, the highest share among Development Assistance Committee (DAC) members in 2023. Japan’s ODA decreased in 2024 to USD 16.8 billion (preliminary data), representing 0.39% of gross national income (GNI).
In 2022-23, Japan committed 67% of its total bilateral allocable ODA in support of the environment and the Rio Conventions, down from 72.7% in 2020-21. The DAC average was 39% in 2022-23. Four per cent of screened bilateral allocable ODA focused on environmental issues as a principal objective, compared with the DAC average of 9.6%. Sixty-five per cent of total bilateral allocable ODA focused on climate change overall, down from 72.2% in 2020-21 (the DAC average was 34.8%). Japan had a greater focus on mitigation (50.1%) than on adaptation (21.5%) in 2022-23. Two per cent of screened bilateral allocable ODA focused on biodiversity overall, down from 1.7% in 2020-21 (the DAC average was 7.6%). Japan committed USD 1.3 billion in support of the conservation and sustainable use of the ocean in 2023, USD 1.2 billion more than in 2022. The 2023 value is equivalent to 4.9% of Japan’s bilateral allocable ODA. (OECD, 2025[6]).
References
[3] CBD (2022), Country profiles: Japan, https://www.cbd.int/countries/profile?country=jp.
[2] IEA (2021), Japan 2021 Energy Policy Review, OECD Publishing, Paris, https://doi.org/10.1787/72bb987a-en.
[6] OECD (2025), Development Co-operation Profiles, OECD Publishing, Paris, https://www.oecd.org/en/publications/development-co-operation-profiles_04b376d7-en/japan_705ac350-en.html.
[1] OECD (2025), Environmental Performance Review of Japan, OECD Publishing, Paris, https://doi.org/10.1787/583cab4c-en.
[5] OECD (2024), Pricing Greenhouse Gas Emissions 2024: Gearing Up to Bring Emissions Down, OECD Series on Carbon Pricing and Energy Taxation, OECD Publishing, Paris, https://doi.org/10.1787/b44c74e6-en.
[4] OECD (2023), OECD Inventory of Support Measures for Fossil Fuels: Country Notes, OECD Publishing, Paris, https://doi.org/10.1787/5a3efe65-en.
JAPAN 2024, Center for Global Environmental Research, Earth System Division, National Institute for Environmental Studies, Japan, 2024. Available at: GHG Inventories｜Greenhouse Gas Inventory Office of Japan｜National Institute for Environmental Studies (nies.go.jp)
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