Enabling energy system transition toward decarbonization in Japan through energy service demand reduction

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 role of energy service demand reduction. To this end, we used a detailed bottom-up energy system model in conjunction with an energy service demand model to explore energy system changes and their cost implications. The results indicate that final energy demand in 2050 can be cut by 37% relative to the no-policy case through energy service demand reduction measures. Although the lack of carbon capture and storage would cause mitigation costs to double or more, these economic impacts can be offset by energy service demand reduction. Among energy demand sectors, the impact of industrial service demand reduction is largest, as it contributes to reducing residual emissions from the industry sector. These findings highlight the importance of energy service demand reduction measures for meeting national climate goals in addition to technological options

Driving forces underlying sub-national carbon dioxide emissions within the household sector and implications for the Paris Agreement targets in Japan

This study investigated insights into reducing energy-related CO2 emissions in households by examining individual socio-economic drivers at a sub-national level. Specifically, the logarithmic mean Divisia index technique was used to decompose CO2 emission trends into six drivers in all 47 prefectures of Japan during the period from 1990 to 2015. Drivers included the change in the number of households (household effect), distribution of households (distribution effect), household size (size effect), per-capita household energy consumption (consumption effect), household energy choice (choice effect), and sectoral CO2 emission intensity (intensity effect). The results showed that, in contrast to size and the distribution effects, the number of households had a positive, significant effect on CO2 emissions, indicating that recent demographic trends are responsible for the increase in CO2 emissions observed in most of the prefectures during the study period. With regard to effects related to consumption and choice, CO2 emissions due to changes in lifestyle dropped in only seven prefectures and reductions due to changes in sectoral energy choice were seen in only two prefectures in 2015. The intensity effect boosted the emissions of these prefectures the most in 2015 because of the shutdown of nuclear power plants due to the Great East Japan Earthquake. Further, we identified those prefectures that needed to reduce their per-capita energy consumption level in order to attain the reduction targets for household CO2 emissions in 2030 from 2015, given projected changes in demographic trends and recent and projected emission intensities. In order to achieve reductions in total CO2 emissions in line with the Paris Agreement, it is important to prioritize national and local policy interventions for the transfer of new household energy technologies, upgrade household appliances, and encourage people to limit energy consumption in light of the differences in these key drivers in each prefecture

Lysinuric protein intolerance exhibiting renal tubular acidosis/Fanconi syndrome in a Japanese woman

Abstract Lysinuric protein intolerance (LPI), caused by pathogenic variants of SLC7A7, is characterized by protein aversion, failure to thrive, hyperammonemia, and hepatomegaly. Recent studies have reported that LPI can cause multiple organ dysfunctions, including kidney disease, autoimmune deficiency, pulmonary alveolar proteinosis, and osteoporosis. We report the case of a 47‐year‐old Japanese woman who was initially diagnosed with renal tubular acidosis (RTA), Fanconi syndrome, and rickets. At the age of 3 years, she demonstrated a failure to thrive. Urinary amino acid analysis revealed elevated lysine and arginine levels, which were masked by pan‐amino aciduria. She was subsequently diagnosed with rickets at 5 years of age and RTA/Fanconi syndrome at 15 years of age. She was continuously treated with supplementation of vitamin D3, phosphate, and bicarbonate. A renal biopsy at 18 years of age demonstrated diffuse proximal and distal tubular damage with endocytosis‐lysosome pathway abnormalities. Distinctive symptoms of LPI, such as protein aversion and postprandial hyperammonemia were not observed throughout the patient's clinical course. The patient underwent a panel‐based comprehensive genetic testing and was diagnosed with LPI. As the complications of LPI involve many organs, patients lacking distinctive symptoms may develop various diseases, including RTA/Fanconi syndrome. Our case indicates that proximal and distal tubular damages are notable findings in patients with LPI. The possibility of LPI should be carefully considered in the management of RTA/Fanconi syndrome and/or incomprehensible pathological tubular damage, even in the absence of distinctive symptoms; furthermore, a comprehensive genetic analysis is useful for diagnosing LPI

Long-Term Tailor-Made Exercise Intervention Reduces the Risk of Developing Cardiovascular Diseases and All-Cause Mortality in Patients with Diabetic Kidney Disease

This study aimed to determine the effect of long-term exercise on the risk of developing cardiovascular diseases (CVD) and all-cause mortality in patients with diabetic kidney disease (DKD). A single-center, prospective intervention study using propensity score matching was performed over 24 months. The intervention group (n = 67) received six months of individual exercise instruction from a physical therapist, who performed aerobic and muscle-strengthening exercises under unsupervised conditions. New events were defined as the composite endpoint of stroke or CVD requiring hospitalization, initiation of hemodialysis or peritoneal dialysis, or all-cause mortality. The cumulative survival rate without new events at 24 months was significantly higher in the intervention group (0.881, p = 0.016) than in the control group (n = 67, 0.715). Two-way analysis of variance revealed a significant effect of the group factor on high density lipoprotein-cholesterol (HDL-C) which was higher in the intervention group than in the control group (p = 0.004); eGFRcr showed a significant effect of the time factor, which was lower at 24 months than before intervention (p = 0.043). No interactions were observed for all items. In conclusion, aerobic exercises combined with upper and lower limb muscle strengthening for six months reduce the risk of developing CVD and all-cause mortality in patients with DKD