Energy consumption in Japan’s building sector peaked in 2005 and decreased by 16% between 2005 and 2019. Since 2005, electricity use in the sector has largely flattened out and oil use has decreased by around 42%, the main driver of the overall decrease in consumption and declining emissions.53
Direct CO₂ emissions of the building sector have been declining since 2002 reaching around 109 MtCO₂/yr in 2030. The largest decrease in direct CO₂ emissions occurred between 2002 and 2010 (2002 also being the year when overall emissions from the sector peaked). This period of emissions reduction corresponds with the roll out of Japan’s Top Runner Programme, which began in 1998 and is ongoing. The programme sets energy efficiency standards for home appliances which are reviewed every 2 to 3 years.54
As part of its long-term strategy, the Japanese government aims to achieve integrated use of demand and supply in rooftop PV through “sector coupling” of electricity, heat, and mobility. To this end, the government is promoting and/or investing in hydrogen infrastructure, electric vehicle charging stations, information and communication technology for demand side management. Sector coupling is seen as a way to improve efficiency and allow for greater utilisation of renewable electricity.2
The 1.5°C compatible pathways have direct emissions form the building sector falling by 34-48% from 2019 levels by 2030 and reaching net zero between 2040-2052. For most pathways, this drop in emissions is achieved largely through fuel switching, mostly through electrification but also through the use of hydrogen and liquid biofuels. Electricity’s share of final energy in the sector increases from 53% in 2019 to 66-69% by 2030 and 88-89% by 2050, and this is would be concurrent with the rapid increase of renewables in the power sector described above. Total energy demand remains around current levels or decreases slightly out to 2050 and beyond. Where a significantly lower demand is projected, the drop in consumption mostly affects oil and natural gas use. The overarching message is that renewable power will play a primary role in decarbonising the building sector
20NHK. Zenbun: Suga shushou shisei hoshin enzetsu [Full text: Prime Minister Suga’s policy speech]. (2021).
21 Schreyer, F. et al. Common but differentiated leadership: strategies and challenges for carbon neutrality by 2050 across industrialized economies. Environ. Res. Lett. 15, 114016 (2020).
22 Shiraki, H., Sugiyama, M., Matsuo, Y., Komiyama, R. & Fujimori, S. The role of renewables in the Japanese power sector : implications from the EMF35JMIP. Sustain. Sci. (2021) doi:10.1007/s11625-021-00917-y.
26 Kuriyama, A., Tamura, K. & Kuramochi, T. Can Japan enhance its 2030 greenhouse gas emission reduction targets?–Assessment of economic and energy-related assumptions in Japan’s NDC. Energy Policy 328–340 (2019).
28 Kojima, S. & Asakawa, K. Expectations for Carbon Pricing in Japan in the Global Climate Policy Context. in Carbon Pricing in Japan (eds. Arimura, T. H. & Matsumoto, S.) (Springer, 2021). doi:10.1007/978-981-15-6964-7_1.
30 Esteban, M., Zhang, Q. & Utama, A. Estimation of the energy storage requirement of a future 100% renewable energy system in Japan. Energy Policy 47, 22–31 (2012).
31 Esteban, M. et al. 100% renewable energy system in Japan: Smoothening and ancillary services. Appl. Energy 224, 698–707 (2018).
32 Cheng, C., Blakers, A., Stocks, M. & Lu, B. 100% renewable energy in Japan. Energy Convers. Manag. 255, 115299 (2022).
37 In order to guarantee that the derived emissions still achieve the global temperature goal when aggregated together across all assessed countries we assess the distribution of pathways from the median until the 5th percentile to form the higher and lower bound of the 1.5°C compatible range (60-72% below 2013 levels). Emission values are rounded to integers. In the Climate Action Tracker a slightly different methodological choice is used to define a 1.5°C compatible benchmark, where projections are harmonised on a different historical year and the median of the range of 1.5° compatible pathways is used – 62% reduction from 2013 levels by 2030.
38 While Japan’s emissions intensity and energy intensity of GDP have decreased significantly over the last three decades, this has been due to energy efficiency improvements rather than a reduction in fossil fuel share in TPES.26 Indeed, coal’s share in primary energy grew by over 50% since 1990. Please see the Climate Action Tracker’s Data Portal for further details.
39 The transport and industrial sectors accounted for 38% and 24%, respectively, of oil consumption in 2018. Use in the power sector has declined significantly since 2013.27
40 The 2-3 USD/tCO₂ value refers to Japan’s carbon tax. The country also levies a fuel excise tax and has two regional emissions trading systems, in Japan and Saitama. The current ETS prices are around 5 USD/tCO₂.6 Accounting for all carbon pricing instruments, the average effective rate has been estimated to be around 39 USD/tCO₂.28
41 According to Japan Beyond Coal, as of January 2022 Japan has 51 GW of coal-fired power plants in operation (0.6 GW mothballed) and another 6 GW of capacity under development (the majority of this under construction with a small amount in planning phase).
42 Note that Japan’s recent Green Growth Strategy also has nuclear playing a significant role in a future decarbonised power sector.15
44 Fossil fuels with carbon capture and storage (CCS) are a significant component of TPES in some 1.5°C compatible pathways, particularly after 2030. The median of these pathways has fossil fuels with CCS accounting for 29% of TPES in 2050, greater than the 17% share for unabated fossil fuels.
45 The low energy demand 1.5°C compatible pathway has TPES in 2050 at around 5 EJ. Japan’s energy consumption has been decreasing fairly steadily since reaching a peak in 2005 and recent reporting had projected a further decline in the coming years, both due to demographic changes and efficiency improvements.27,29 Projections from the Ministry of Economy, Trade and Industry have TPES decreasing from 509 million kilolitres of oil equivalent (kl) in 2018 to 489 million kl by 2030.
46 This would translate to a compound annual rate of reduction between 7-10% compared to the rate of reduction of 2.5% seen between 2013 and 2019.
47 The upper value in the range implies negative emissions which could result from the use of carbon dioxide removal technologies such as BECCS. At the 25th percentile, the 1.5°C compatible pathways show that around 44 MtCO₂e/yr of GHG emissions would need to be balanced out by 2050. Although the long-term strategy does not give an exact value for the anticipated level of removals from forest carbon sinks and other carbon dioxide removal technologies in 2050, the document does provide an estimate of net carbon removals in 2019 (45.9 MtCO₂).2 This seems to be in line with the projected 2030 GHG removals stated in the updated NDC (47.7 MtCO₂).18
48 Values are for 2019. Renewables include wind, solar, geothermal, hydro, and biofuels.
49 The government has stated that it will pursue nuclear power options as part of their Green Growth Strategy. Specifically, it will support efforts to develop small module reactors, hydrogen production by high-temperature gas-cooled reactors, and fusion energy. The government aims to commercialise the former two technologies by 2030.15
51 Some pathways assume much lower renewables shares (as low as a third in 2050) instead relying on fossil and bioenergy with carbon capture and storage, starting in the 2020s and reaching as much as 65% of the power sector by 2060. Given the significant costs and lead times required for CCS, it is unclear how such fast deployment could be achieved. The same pathways also all assume a return to nuclear power, reaching shares of 30% and absolute values well above pre-Fukushima levels
52 Other recent studies have also modelled viable pathways to a 100% renewable power sector for Japan and explored the implications for storage, ancillary services, and price.30-32
53 Regression analysis of changes in emissions on changes in the use of various energy sources (liquid fuels, gaseous fuels, electricity) over the period 1990 – 2019 shows that changes in emissions were most highly correlated with changes in liquid fuels (oil) consumption. Changes in emissions were also correlated, albeit less so, with changes in gaseous fuels (natural gas) use. For both of these fuels, the correlation with emissions was found to be positive.
54 Efficiency standards for several electrical home appliances were introduced in 1999 while further standards, including for gas stoves and heaters, were introduced in 2002. These standards were set so that full enactment would occur 4 to 6 years after introduction. Thus, for most household appliances, full enactment of energy efficiency standards took place between 2003 and 2010.33 A recent study has shown that the top runner programme has led to a rebound effect whereby greater household consumption negates the energy efficiency gains.34 This effect is consistent with the rising consumption of electricity in the building sector and may explain the levelling out of emissions intensity levels from 2010 onwards.
55 In 2018, Japan’s industrial sector consumed 116 Mtoe including non-energy use (34 Mtoe). Oil accounted for 43% of the total, with coal and natural gas making up 18% and 10% respectively. Electricity accounted for 25% of consumption and biofuels 3%. The majority of industrial fuel consumption was due to the chemical and petrochemical industries (43% in 2018).16 With regards to GDP, here we use the term secondary industry to refer to mining, manufacturing, and construction, as per the Statistical Handbook of Japan.24 Value is current as of 2019. See table 3.3 therein.
56 Japan’s push for energy efficiency improvements began as a response to the two oil crises of the 1970s, as exemplified by the Energy Efficiency Act enacted in 1979. The Act has been updated with major revisions since then, such as the introduction of the aforementioned Top Runner Program in 1998. The latest revision to the Act occurred in 2018.35
57 The consumption of electricity decreased after by around 20% between 2006 and 2008 due to the Global Financial Crisis and has yet to recover.
58 This average reduction takes into account the significant declines which occurred during the Asian (1997) and Global (2007-08) Financial Crises.
59 The buildings and industry sectors have a greater overall energy demand and thus a greater absolute reliance on imported fossil fuels. This takes into account both direct fuel use and electricity consumption (indirect use). Note that in 2018, Japan’s import dependency for crude oil, LNG, and coal was 99.7%, 97.5%, and 99.3% respectively.36
60 The 5th Strategic Energy Plan put forth a goal of a 50.3 million kilolitre (42.8 Mtoe) reduction in energy demand by 2030. This would be achieved through reductions in the industry, transport, commercial, and residential sectors of 10.42, 16.07, 12.26, and 11.6 million kilolitres respectively.16
61 The other two countries, China and the UK, aim to meet their targets by 2035 and 2030 respectively.