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National-level climate actions will be vital in achieving global temperature goals in the coming decades. Near-term (2025–2030) plans are laid out in Nationally Determined Contributions; the next step is the submission of long-term strategies for 2050. At present, national scenarios underpinning long-term strategies are poorly coordinated and incompatible across countries, preventing assessment of individual nations’ climate policies. Here we present a systematic and standardized, yet flexible, scenario framework varying 2050 emissions to build long-term national energy and climate mitigation scenarios. Applying the framework to six major Asian countries reveals individual challenges in energy system transformation and investment needs in comparable scenarios. This framework could be a starting point for comprehensive assessments as input to the Global Stocktake over the coming years., 世界各国の2050年の温室効果ガス削減目標を分析するための国際的な研究フレームワークの提案. 京都大学プレスリリース. 2021-05-28., Pathways to global climate targets. 京都大学プレスリリース. 2021-06-01.

Thailand’s Nationally Determined Contribution (NDC) submitted to the United Nations Framework Convention on Climate Change (UNFCCC) aims to reduce 20 to 25% of greenhouse gas (GHG) emissions with respect to the projected reference level of NDC in 2030, respectively, in its unconditional and conditional scenarios. The Intergovernmental Panel on Climate Change (IPCC) states that limiting global temperature rise to 1.5°C would require net zero carbon dioxide emissions globally by around 2050. Thailand’s current energy system is highly fossil fuel dependent and requires enormous transformations to achieve more stringent GHG emission reduction targets beyond its NDC. This paper seeks to estimate the level and the intensities of Thailand’s energy system and their economy-wide effects post-2030 under the business as usual and 16 GHG emission reduction scenarios ranging from 30 to 100% by 2050. A computable general equilibrium analysis using the AIM/Hub model is employed to estimate the macroeconomic impacts of meeting the unconditional and conditional emission reductions of Thailand’s NDC in 2030 along with varying GHG emission reductions in 2050. Results show that renewables – constituting solar, wind, biomass and hydro and carbon capture and storage (CCS) technologies account for more than 95% in the power generation mix by 2050, if 100% GHG emission reduction from the 2010 level is to be achieved. Electricity generation based on biomass both with and without CCS will occupy a major share in the investments by 2050 in all the conditional and unconditional NDC scenarios. A rapid increase in carbon sequestration occurs from 2040 onwards through the deployment of CCS and bioenergy with CCS (BECCS) technologies in all the conditional and unconditional NDC scenarios. Carbon prices lie in the range of 3.4–266.2 US$/tCO2eq during 2025–2050 to achieve 100% GHG emission reductions in 2050. Imposition of early stringent mitigation target lowers the carbon prices in the conditional scenarios towards 2050 when compared to the unconditional scenarios. The rapid uptake of CCS, energy efficiency improvements and electrification of the end-use technologies are identified to be the key measures to transform the energy system of Thailand. Key policy insightsBy 2050, the Thai economy would face a higher fall in both the GDP and household consumption in the unconditional scenarios than those in the conditional scenarios at all levels of GHG emission reduction.Results indicate that early mitigation efforts can be less costly than the delayed ones in the long-term.The cumulative investment needed to achieve decarbonization in Thailand is estimated to exceed 355 billion US$2005 over the period 2010–2050 in the 100% GHG reduction scenarios.The transmission and distribution investments in the power sector need to increase by 30–35% to attain 100% GHG emission reductions during 2010–2050.The trade deficit improves by up to 23–29% in the various GHG mitigation scenarios in 2050. By 2050, the Thai economy would face a higher fall in both the GDP and household consumption in the unconditional scenarios than those in the conditional scenarios at all levels of GHG emission reduction. Results indicate that early mitigation efforts can be less costly than the delayed ones in the long-term. The cumulative investment needed to achieve decarbonization in Thailand is estimated to exceed 355 billion US$2005 over the period 2010–2050 in the 100% GHG reduction scenarios. The transmission and distribution investments in the power sector need to increase by 30–35% to attain 100% GHG emission reductions during 2010–2050. The trade deficit improves by up to 23–29% in the various GHG mitigation scenarios in 2050.

Delaying climate mitigation action and allowing a temporary overshoot of temperature targets require large-scale carbon dioxide removal (CDR) in the second half of this century that may induce adverse side effects on land, food and ecosystems. Meanwhile, meeting climate goals without global net-negative emissions inevitably needs early and rapid emission reduction measures, which also brings challenges in the near term. Here we identify the implications for land-use and food systems of scenarios that do not depend on land-based CDR technologies. We find that early climate action has multiple benefits and trade-offs, and avoids the need for drastic (mitigation-induced) shifts in land use in the long term. Further long-term benefits are lower food prices, reduced risk of hunger and lower demand for irrigation water. Simultaneously, however, near-term mitigation pressures in the agriculture, forest and land-use sector and the required land area for energy crops increase, resulting in additional risk of food insecurity.

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.

For isolated single cells on a substrate, the intracellular stiffness, which is often measured as the Young’s modulus, E, by atomic force microscopy (AFM), depends on the substrate rigidity. However, little is known about how the E of cells is influenced by the surrounding cells in a cell population system in which cells physically and tightly contact adjacent cells. In this study, we investigated the spatial heterogeneities of E in a jammed epithelial monolayer in which cell migration was highly inhibited, allowing us to precisely measure the spatial distribution of E in large-scale regions by AFM. The AFM measurements showed that E can be characterized using two spatial correlation lengths: the shorter correlation length, l(S), is within the single cell size, whereas the longer correlation length, l(L), is longer than the distance between adjacent cells and corresponds to the intercellular correlation of E. We found that l(L) decreased significantly when the actin filaments were disrupted or calcium ions were chelated using chemical treatments, and the decreased l(L) recovered to the value in the control condition after the treatments were washed out. Moreover, we found that l(L) decreased significantly when E-cadherin was knocked down. These results indicate that the observed long-range correlation of E is not fixed within the jammed state but inherently arises from the formation of a large-scale actin filament structure via E-cadherin-dependent cell-cell junctions.

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., Applied Energy, 228, pp.2321-2332; 2018

This study investigated the factors behind the historical changes in CO2 emissions of the Japanese manufacturing industry as a whole and by sector at the prefectural level. We decomposed the changes of CO2 emissions in 47 prefectures from 1990 to 2013 into four factors (carbon intensity, energy intensity, structure, and activity effects) using the logarithmic mean Divisia index method. We found that energy intensity, structure, and activity effects were more influential in the changes of emissions than the carbon intensity effect, although the most influential factor varied by prefecture. Among the eight considered industrial sectors of Japan's manufacturing industry, the changes in the chemistry and metal sectors were particularly complex. Thus, improvements of the energy intensity and production in these two sectors should be prioritized. We also conducted detailed analysis of the decomposed factors in three selected prefectures based on cluster analysis.

The road transport sector accounted for 18.8% of global CO2 emissions in 2016. Regional efforts are indispensable for reducing automobile emissions, especially considering the diversity in regional transportation systems. Existing studies of automobile emissions have focused on nationwide transportation systems or differences in city size without considering regionality and long-term changes in vehicle occupancy. In this study, we decomposed national and regional automobile emissions in Japan between 1990 and 2015 by the Logarithmic Mean Divisia Index method. Statistical data that took vehicle occupancy into account were used. Results showed that nationwide vehicle occupancy increased (due to increased vehicle size and vehicle ownership), which increased emissions by 15.2% compared to 1990 levels. In highly populated regions, fuel efficiency decreased earlier than other regions thanks to the strengthening of ordinances regarding air pollution. In Western Japan, which includes less-populated prefectures, the rising popularity of mini-vehicles resulted in increased vehicle ownership and a decrease in occupancy but also led to improvements in fuel economy. To reduce automobile CO2 emissions, it will be essential to improve fuel efficiency and to increase vehicle occupancy through mechanisms, such as ridesharing and vehicle right sizing.

Thermus thermophilus is an extremely thermophilic eubacterium that produces various polyamines. Aminopropylagmatine ureohydrolase (SpeB) and SAM decarboxylase-like protein 1 (SpeD1) are involved in the biosynthesis of spermidine from arginine. Because long and branched polyamines in T. thermophilus are synthesized from spermidine, the speB and speD1 gene-deleted strains (ΔspeB and ΔspeD1, respectively) cannot synthesize long and branched polyamines. Although neither strain grew at high temperatures (75°C) in minimal medium, both strains survived at 80°C when they were cultured at 70°C until the mid-log phase and then shifted to 80°C. We therefore prepared the ΔspeB and ΔspeD1 cells using this culture method. Microscopic analysis showed that both strains can survive for 10 h after the temperature shift. Although the modification levels of 2'-O-methylguanosine at position 18, N

Thermus thermophilus is an extremely thermophilic eubacterium that produces various polyamines. Aminopropylagmatine ureohydrolase (SpeB) and SAM decarboxylase-like protein 1 (SpeD1) are involved in the biosynthesis of spermidine from arginine. Because long and branched polyamines in T. thermophilus are synthesized from spermidine, the speB and speD1 gene-deleted strains (ΔspeB and ΔspeD1, respectively) cannot synthesize long and branched polyamines. Although neither strain grew at high temperatures (\textgreater75°C) in minimal medium, both strains survived at 80°C when they were cultured at 70°C until the mid-log phase and then shifted to 80°C. We therefore prepared the ΔspeB and ΔspeD1 cells using this culture method. Microscopic analysis showed that both strains can survive for 10 h after the temperature shift. Although the modification levels of 2'-O-methylguanosine at position 18, N(7) -methylguanosine at position 46, 5-methyluridine at position 54 and N(1) -methyladenosine at position 58 in the class I tRNA from both strains were normal, amounts of tRNA(Tyr) , tRNA(His) , rRNAs and 70S ribosomes were decreased after the temperature shift. Furthermore, in vivo protein synthesis in both strains was completely lost 10 h after the temperature shift. Thus, long and branched polyamines are required for at least the maintenance of 70S ribosome and some tRNA species at high temperatures.

Electric power demand management will play an important role in the creation of smart-energy communities. We are conducting a field experiment on the real-time feedback of electric power consumption via smart meters and tablet PCs with the participation of 51 households on Nushima Island, one of Japan's remote islands. Our estimate of the effect of feedback in reducing power demand by panel data analysis has revealed that such feedback achieves a saving of 7.6 percent in electric power demand.

Holding the global increase in temperature caused by climate change well below 2 °C above pre-industrial levels, the goal affirmed by the Paris Agreement, is a major societal challenge. Meanwhile, food security is a high-priority area in the UN Sustainable Development Goals, which could potentially be adversely affected by stringent climate mitigation. Here we show the potential negative trade-offs between food security and climate mitigation using a multi-model comparison exercise. We find that carelessly designed climate mitigation policies could increase the number of people at risk of hunger by 160 million in 2050. Avoiding these adverse side effects would entail a cost of about 0.18% of global gross domestic product in 2050. It should be noted that direct impacts of climate change on yields were not assessed and that the direct benefits from mitigation in terms of avoided yield losses could be substantial, further reducing the above cost. Although results vary across models and model implementations, the qualitative implications are robust and call for careful design of climate mitigation policies taking into account agriculture and land prices.

In 2004, a sever drift wood hazard caused by fallen trees drifting in muddy flows and overflowing at river bridges happened in many steep small-scale rivers of Ehime Prefecture. In this paper, a countermeasure in which the rail on the bridge girder is removed and some of flowing flood water overflows on the bridge girder like a sinking bridge is proposed and the effect of the countermeasure is examined through runoff experiments in hydraulic steep channels. As a result, it was made clear that the countermeasure removing the rails is a very effective one which reduces a destructive power of overflooding water to one third.

Phase separation of binary blends composed of a polystyrene derivative (PS) and poly (vinyl methyl ether) (PVME) with a lower critical solution temperature (LCST) was experimentally induced by two different methods: heating and UV light irradiation. Using laser light scattering combined with the temperature jump (T-jump) technique, it was demonstrated that in the case of heating, the mixture undergoes phase separation via the nucleation-and-growth (NG) and the spinodal decomposition (SN) processes under shallow and deep quenches, respectively. Particularly, the crossover from the spinodal decomposition to the nucleation-and-growth process was observed at long time under a deep T-jump by light-scattering experiments. On the other hand, in the photo-crosslink case, the PS/PVME blends undergo a nucleation-and-growth process upon irradiation with weak light intensity, whereas the mixture exhibits the spinodal decomposition under irradiation with strong light intensity. From the analysis of the light-scattering data obtained for the blends under the photo-crosslink, the kinetic data reveal the suppression of morphologies having large characteristic length scales. This feature clearly differs from the phase separation induced by heating where no mode-suppression process was observed. It was also found that distribution of the characteristic length scales (the regularity) of the morphology becomes narrow as the phase separation proceeds for reacting blends, whereas it becomes broader as the phase separation proceeds by heating, revealing the important roles of reaction in the suppression of fluctuations with long wavelengths. These experimental results establish a method to control the length scales and the regularity of the morphology of polymer blends by chemical reaction.