Ken Oshiro

Hydrogen-based energy carriers, including hydrogen, ammonia and synthetic hydrocarbons, are expected to help reduce residual carbon dioxide emissions in the context of the Paris Agreement goals, although their potential has not yet been fully clarified in light of their competitiveness and complementarity with other mitigation options such as electricity, biofuels and carbon capture and storage (CCS). This study aimed to explore the role of hydrogen in the global energy system under various miti

This study assesses Japan's emission pathways aimed at net-zero emissions by 2050, as implied by the Paris Agreement's global climate goal of pursuing efforts to limit the temperature rise to 1.5 °C. Based on a scenario analysis performed using AIM/Enduse [Japan], Japan's energy supply sector requires a radical transformation, including reliance on carbon dioxide removal options such as bioenergy with carbon capture and storage (BECCS) to attain net-zero emissions by 2050 without substantial soc

Japan’s mid-century strategy for reducing greenhouse gas emissions by 80% in 2050 would require large-scale energy system transformation and associated increases in mitigation costs. Nevertheless, the role of energy demand reduction, especially reductions related to energy services such as behavioral changes and material use efficiency improvements, have not been sufficiently evaluated. This study aims to identify key challenges and opportunities of the decarbonization goal when considering the

For countries without sufficient fossil fuel resources such as Japan, climate policies in the mid- to long term need to satisfy requirements not only for decarbonisation but also for energy security in the context of limitations on renewable energies and nuclear power. This study assesses the feasibility of decarbonization pathways to 2050 and their effects on energy security, considering the latest energy and climate policies in Japan using the AIM/Enduse model. The analysis illustrates that de

Abstract This study assesses Japan’s mid-century low-emission pathways using both national and global integrated assessment models in the common mitigation scenario framework, based on the carbon budgets corresponding to the global 2 °C goal. We examine high and low budgets, equal to global cumulative 1600 and 1000 Gt-CO 2 (2011–2100) for global models, and 36 and 31 Gt-CO 2 (2011–2050) in Japan for national models, based on the cost-effectiveness allocation performed by the global models. The i

Climate change mitigation generally require rapid decarbonization in the power sector, including phase-out of fossil fuel-fired generators. Given recent technological developments, co-firing of hydrogen or ammonia, could help decarbonize fossil-based generators, but little is known about how its effects would play out globally. Here, we explore this topic using an energy system model. The results indicate that hydrogen co-firing occurs solely in stringent mitigation like 1.5 °C scenarios, where

Abstract Japan’s mid-century strategy to reduce greenhouse gas (GHG) emissions by 80% by 2050 requires rapid energy system changes, which may lead to stranded assets in fossil fuel-related infrastructure. Existing studies have shown that massive stranding of assets in the energy supply side is possible; few studies have involved economy-wide stranded asset analysis. In this study, we estimated stranded investments in both the energy supply and demand sectors in Japan in the context of near-term

To reach net-zero carbon emissions, most climate change mitigation scenarios model a rapid transition from hydrocarbon-based energy to renewables, wide-scale electrification, and offsets to mitigate residual emissions. This requires phasing out existing hydrocarbon infrastructure and adjustments to electrification. Carbon capture and utilization (CCU) to produce synthetic fuels could be an alternative way to reach net zero while maintaining some existing energy infrastructure and minimizing the

Japan has formulated a net-zero emissions target by 2050. Existing scenarios consistent with this target generally depend on carbon dioxide removal (CDR). In addition to domestic mitigation actions, the import of low-carbon energy carriers such as hydrogen and synfuels and negative emissions credits are alternative options for achieving net-zero emissions in Japan. Although the potential and costs of these actions depend on global energy system transition characteristics which can potentially be

Wood is well-recognized as a renewable resource that can contribute to the reduction of environmental load and it has long been used as a material in the building sector. The LCA database for buildings (established by the Architectural Institute of Japan) has been developed and utilized to evaluate the reduction of environmental load through the use of wood materials. However, this method does not evaluate the environmental load incurred through the production and transportation of imported wood