Comparative assessment of GHG mitigation scenarios for Japan in 2030

The study analyzes 48 bottom-up energy system scenarios for Japan's 2030 GHG emissions. It finds that high-mitigation scenarios consistent with a 2°C target result in emissions 16-39% below 1990 levels. The authors argue that a minimum reduction of 25% from 1990 levels is necessary, which could be achieved through a combination of restarting nuclear reactors, increasing renewable energy and CCS deployment, and significantly reducing total final consumption (TFC). The paper emphasizes that the choice between coal and natural gas for electricity is as critical as the share of renewables, noting that unabated coal-fired power must remain below 21% to achieve reductions exceeding 20% from 1990 levels.

• Scenarios categorized as having the highest mitigation effort, including those aligned with a global 2°C target, project GHG emissions between 16% and 39% below 1990 levels, with nuclear power shares ranging from 0% to 29%.
• A GHG emissions reduction of more than 25% from 1990 levels (or 32% from 2005 levels) is identified as the minimum effort level required for Japan to contribute to the global 2°C target, assuming the restart of most existing nuclear reactors and the deployment of renewable electricity.
• To achieve a 25% reduction from 1990 levels with a 15% nuclear power share, Japan would need a 30% share of renewable/CCS electricity, a 20% reduction in total final consumption (TFC) from 2010 levels, and a 60% gas-fired power share among unabated fossil fuel generation.
• A 25% GHG reduction is possible without nuclear power if the share of renewable/CCS electricity is increased to 35% and TFC is reduced by 25% from 2010 levels.
• For all analyzed scenarios achieving GHG reductions greater than 20% from 1990 levels, the share of unabated coal-fired electricity was consistently lower than 21%.
• The choice of fuel for fossil fuel-fired electricity is critical; decreasing the gas power ratio from 60% to 40% would require an increase in the renewable/CCS electricity share by 3 to 9 percentage points to maintain the same emission levels.
• The 'Warsaw Target' for 2020 is considered lenient and may hinder TFC reductions toward 2030; if Japan adheres to this target and delays action, the required annual TFC reduction rate for 2020-2030 would double from 0.9%/yr to 1.8%/yr to reach a 25% reduction by 2030.
• Regression analysis indicates that increasing renewable/CCS electricity generation by one TWh reduces GHG emissions by 0.630 Mt-CO2e, which is approximately 5% more effective than a corresponding increase in nuclear electricity generation (0.593 Mt-CO2e).

APA

Kuramochi, T., Wakiyama, T., & Kuriyama, A. (2015). Comparative assessment of GHG mitigation scenarios for Japan in 2030. World Resources Institute. https://wriorg.s3.amazonaws.com/s3fs-public/uploads/IGES-OCN_2030scenarios_Final3.pdf

Chicago

Kuramochi, Takeshi, Takako Wakiyama, and Akihisa Kuriyama. Comparative assessment of GHG mitigation scenarios for Japan in 2030. World Resources Institute, 2015. https://wriorg.s3.amazonaws.com/s3fs-public/uploads/IGES-OCN_2030scenarios_Final3.pdf.

Wikipedia

{{cite report |last1=Kuramochi |first1=Takeshi |last2=Wakiyama |first2=Takako |last3=Kuriyama |first3=Akihisa |title=Comparative assessment of GHG mitigation scenarios for Japan in 2030 |publisher=World Resources Institute |date=May 2015 |url=https://wriorg.s3.amazonaws.com/s3fs-public/uploads/IGES-OCN_2030scenarios_Final3.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{kuramochi2015comparative, author = {Kuramochi, Takeshi and Wakiyama, Takako and Kuriyama, Akihisa}, title = {{Comparative assessment of GHG mitigation scenarios for Japan in 2030}}, institution = {World Resources Institute}, year = {2015}, month = may, url = {https://wriorg.s3.amazonaws.com/s3fs-public/uploads/IGES-OCN_2030scenarios_Final3.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }