Ken'ichi Matsumoto

Bio: Ken'ichi Matsumoto is an academic researcher from Japan Agency for Marine-Earth Science and Technology. The author has contributed to research in topics: Renewable energy & Greenhouse gas. The author has an hindex of 19, co-authored 78 publications receiving 3787 citations. Previous affiliations of Ken'ichi Matsumoto include Nagasaki University & Panasonic.

The RCP greenhouse gas concentrations and their extensions from 1765 to 2300

Abstract: We present the greenhouse gas concentrations for the Representative Concentration Pathways (RCPs) and their extensions beyond 2100, the Extended Concentration Pathways (ECPs). These projections include all major anthropogenic greenhouse gases and are a result of a multi-year effort to produce new scenarios for climate change research. We combine a suite of atmospheric concentration observations and emissions estimates for greenhouse gases (GHGs) through the historical period (1750-2005) with harmonized emissions projected by four different Integrated Assessment Models for 2005-2100. As concentrations are somewhat dependent on the future climate itself (due to climate feedbacks in the carbon and other gas cycles), we emulate median response characteristics of models assessed in the IPCC Fourth Assessment Report using the reduced-complexity carbon cycle climate model MAGICC6. Projected 'best-estimate' global-mean surface temperature increases (using inter alia a climate sensitivity of 3°C) range from 1.5°C by 2100 for the lowest of the four RCPs, called both RCP3-PD and RCP2.6, to 4.5°C for the highest one, RCP8.5, relative to pre-industrial levels. Beyond 2100, we present the ECPs that are simple extensions of the RCPs, based on the assumption of either smoothly stabilizing concentrations or constant emissions: For example,

An emission pathway for stabilization at 6 Wm−2 radiative forcing

Abstract: Representative Concentration Pathway 6.0 (RCP6) is a pathway that describes trends in long-term, global emissions of greenhouse gases (GHGs), short-lived species, and land-use/land-cover change leading to a stabilisation of radiative forcing at 6.0 Watts per square meter (Wm−2) in the year 2100 without exceeding that value in prior years. Simulated with the Asia-Pacific Integrated Model (AIM), GHG emissions of RCP6 peak around 2060 and then decline through the rest of the century. The energy intensity improvement rates changes from 0.9% per year to 1.5% per year around 2060. Emissions are assumed to be reduced cost-effectively in any period through a global market for emissions permits. The exchange of CO2 between the atmosphere and terrestrial ecosystem through photosynthesis and respiration are estimated with the ecosystem model. The regional emissions, except CO2 and N2O, are downscaled to facilitate transfer to climate models.

Historical energy security performance in EU countries

Abstract: It is vitally important for all countries to ensure they have a secure energy supply. This is especially true for European Union (EU) countries, because of geopolitical considerations and ongoing reforms of energy markets. This study applied time-series clustering approaches and three energy security indicators based on the Shannon–Wiener diversity index. The aim was to enhance understanding of how energy security of EU countries, in terms of energy supply, has evolved. An overall improvement in energy security in most EU countries between 1978 and 2014 was identified, with Denmark and the Czech Republic evidencing the greatest improvements. The main driver of improvement has been diversification of primary energy sources. Factors relating to imports (share and diversity of the origins of imports) have also substantially influenced improvement levels. Three groups of countries were identified using cluster analysis: (1) consistently high levels of energy security and showed moderate improvements over time; (2) lower levels of energy security than those in the first group, and also evidenced moderate improvements; and (3) initially low energy security levels, yet followed by significant improvements. The first and third groups were of particular interest because the former reveals best practices while the policies of the latter, in leading to improvement, can serve as guides for other countries.

Energy security in East Asia under climate mitigation scenarios in the 21st century

Abstract: Japan, China, and South Korea depend heavily on imports for most of their energy. This study aims to investigate how energy security in these three East Asian countries will change in the future under climate mitigation policy scenarios. The study will help researchers and policy makers to better understand the relationship between climate and energy issues that will arise in relevant policy discussions. The analysis was conducted using a computable general equilibrium model. A reference scenario and two policy scenarios based on the Representative Concentration Pathways adopted by the Intergovernmental Panel on Climate Change are analyzed and compared between primary energy, fossil fuels imports, and diversification of energy sources. The findings suggest that to reduce greenhouse gas emissions, the three East Asian countries need to shift their energy structures from currently dominant fossil fuels to renewables and nuclear power. The lower the target of allowable emissions, the larger the required shifts will have to be. Among fossil fuels, coal use in particular must significantly decrease. Such structural shifts improve energy self-sufficiency, thus enhancing energy security. However, the impact of diversification of energy sources (measured by the Herfindahl index) under climate mitigation scenarios differs by country and scenario. Until 2050, diversity improves in all three countries relative to the base year. After that, in some countries the diversity should decline because of high dependence on a specific energy source. Overall, it is revealed that energy security improves along with climate mitigation. This improvement will also contribute to the economy by reducing energy procurement risks.

The representative concentration pathways: an overview

Abstract: This paper summarizes the development process and main characteristics of the Representative Concentration Pathways (RCPs), a set of four new pathways developed for the climate modeling community as a basis for long-term and near-term modeling experiments. The four RCPs together span the range of year 2100 radiative forcing values found in the open literature, i.e. from 2.6 to 8.5 W/m 2 . The RCPs are the product of an innovative collaboration between integrated assessment modelers, climate modelers, terrestrial ecosystem modelers and emission inventory experts. The resulting product forms a comprehensive data set with high spatial and sectoral resolutions for the period extending to 2100. Land use and emissions of air pollutants and greenhouse gases are reported mostly at a 0.5×0.5 degree spatial resolution, with air pollutants also provided per sector (for well-mixed gases, a coarser resolution is used). The underlying integrated assessment model outputs for land use, atmospheric emissions and concentration data were harmonized across models and scenarios to ensure consistency with historical observations while preserving individual scenario trends. For most variables, the RCPs cover a wide range of the existing literature. The RCPs are supplemented with extensions (Extended Concentration Pathways, ECPs), which allow

Anthropogenic and Natural Radiative Forcing

Abstract: This chapter should be cited as: Myhre, G., D. Shindell, F.-M. Bréon, W. Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Coordinating Lead Authors: Gunnar Myhre (Norway), Drew Shindell (USA)

Climate change 2014 - Mitigation of climate change

Abstract: The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.