What is Japan's pathway to limit global warming to 1.5°C?

Under the Highest Possible Ambition scenario, coal and oil would be practically phased out by 2030 as well as gas by 2040. While these could be ambitious phase-out target years, Japan’s stalled progress in sufficiently decarbonising over the last few critical years has added additional difficulty. Meanwhile, renewables would scale up to 50% of power mix by 2030 and 88% by 2040. This would cut Japan’s CO₂ emissions by two-thirds by 2030 from 2023 levels and enable full power sector’s decarbonisation by 2040.

By contrast, Japan continues to plan for a power mix containing 41% thermal generation in 2030 and 30–40% in 2040.³3^,44 Renewable targets of 36–38% by 2030 and 40–50% by 2040 therefore fall short of levels required for 1.5°C aligned pathways.⁵5^,66 Although energy security concerns are cited as the reason to maintain a high share of fossil fuels in the mix, Japan can meet its domestic demand through renewables, which would allow it to reduce dependence on volatile fossil fuel markets which led to gasoline price surge in Japan in March 2026 due to the Iran war.⁷7^,88

The Seventh Strategic Energy Plan (2025) positions LNG as a transition fuel and stresses its importance even beyond carbon neutrality in 2050, including the need to secure long-term LNG contracts through public-private partnerships. ⁹9 This enables Japan to maintain its current level of 80% of its LNG import from long-term contracts, even beyond 2050, despite its declining domestic demand since 2018, creating risks of carbon lock-in and oversupply.¹⁰10^,1111 Government support for LNG remains strong, with the newly elected government signing a USD 33 bn trade deal with the United States for a 9.2 GW gas project, the largest gas generation project in the world.¹²12

Amid domestic oversupply, a policy target of handling 100 million tons of LNG annually by FY 2030, and expansions of its international trading network, Japan is shifting from a major importer to a global LNG trader.¹³13^,1414 It resold about 37% of imported LNG in 2023, up from 16% in 2018, with volumes for external trade rising from just under 15 million tons in FY 2018 to 38 million tons in FY 2023.¹⁵15

Japan is also actively investing in gas infrastructure across Asia-Pacific, including Vietnam, the Philippines, Thailand, Indonesia, and Bangladesh. This exports significant decarbonisation risk to the region, as LNG can have a higher lifecycle GHG footprint than coal over a 20-year horizon when upstream methane leakage, processing, and transport are included.¹⁶16^,1717 To align with 1.5°C compatible pathways, Japan would need to reduce its reliance on LNG, cease funding for overseas fossil fuel projects, and accelerate its progress on renewable energy deployment.

Current policy is reinforcing the role of nuclear power in Japan’s grid. Since 2015, 15 reactors have restarted following their complete suspension after the 2011 Fukushima accident.¹⁸18^,1919