Simulating second-generation herbaceous bioenergy crop yield using the global hydrological model H08 (v.bio1)

Large-scale deployment of bioenergy plantations would have adverse effects on water resources. There is an increasing need to ensure the appropriate inclusion of the bioenergy crops in global hydrological models. Here, through parameter calibration and algorithm improvement, we enhanced the global hydrological model H08 to simulate the bioenergy yield from two dedicated herbaceous bioenergy crops: Miscanthus and switchgrass. Site-specific evaluations showed that the enhanced model had the ability to simulate yield for both Miscanthus and switchgrass, with the calibrated yields being well within the ranges of the observed yield. Independent country-specific evaluations further confirmed the performance of the H08 (v.bio1). Using this improved model, we found that unconstrained irrigation more than doubled the yield under rainfed condition, but reduced the water use efficiency (WUE) by 32 % globally. With irrigation, the yield in dry climate zones can exceed the rainfed yields in tropical climate zones. Nevertheless, due to the low water consumption in tropical areas, the highest WUE was found in tropical climate zones, regardless of whether the crop was irrigated. Our enhanced model provides a new tool for the future assessment of bioenergy–water tradeoffs

Adapting global shared socio-economic pathways for national scenarios in Japan

A Correction to this article was published. This article has been updated.Shared socio-economic pathways (SSPs) are alternative global development scenarios focused on the mitigation of and adaptation to climate change. However, global SSPs would need revised versions for regional or local assessment, which is the so-called extended version, because global narratives may lack region-specific important drivers, national policy perspectives, and unification of data for each nation. Thus, it is necessary to construct scenarios that can be used for governments in response to the SSPs to reflect national and sub-national unique situations. This study presents national SSP scenarios, specifically focusing on Japan (hereafter, Japan SSPs), as well as a process for developing scenarios that qualitatively links to global SSPs. We document the descriptions of drivers and basic narratives of Japan SSPs coherent with global SSPs, based on workshops conducted by local researchers and governments. Moreover, we provide a common data set of population and GDP using the national scale. Japan SSPs emphasized population trends different from global SSPs and influencing factors, citizen participation, industrial development resulting from economic change, distribution, and inequality of sub-national population, among others. We selected data sets from existing population projections that have been widely used by Japanese researchers; the data show that the population and GDP of Japan SSPs are expected to be about 20-25% less than global SSPs by 2100

How many hot days and heavy precipitation days will grandchildren experience that break the records set in their grandparents’ lives?

孫は祖父母が遭遇しないような暑い日と大雨を何度経験するのか? --極端な気象現象の変化に関する世代間不公平性とその地域間不公平性の評価--. 京都大学プレスリリース. 2021-06-14.One of the major barriers to climate communication is that climate change is often presented to the public in such a way that impacts seem distant in time. To improve how climate change resonates with people, we propose a simple indicator: how many extreme events (hot days and heavy precipitation days) are grandchildren projected to experience that their grandparents will not experience in their lives? We analyse the Coupled Model Intercomparison Project Phase 6 ensemble. During grandchildren's lifetime (2020–2100) under the shared socioeconomic pathway 5–8.5 (SSP5-8.5), in some tropical regions, they are projected to experience >1000 hot days and >5 heavy precipitation days breaking records set in their grandparents' lifetime until 2040. These numbers of unprecedented hot days and heavy precipitation days under SSP5-8.5 are greater in countries with lower CO₂ emissions and income per capita than in countries with higher CO₂ emissions and income per capita. We show that not only the numbers of unprecedented hot days and heavy precipitation days but also their unevenness across countries can be significantly lowered in the SSP1-2.6 scenario, which is consistent with the 2 °C goal of the Paris Agreement. This new approach would help adults easily understand how their climate change mitigation efforts could decrease the unprecedented extreme events during youths' lifetime and reduce the intergenerational and intragenerational inequalities regarding extreme events

Demand-side decarbonization and electrification: EMF 35 JMIP study

Japan’s long-term strategy submitted to the United Nations Framework Convention on Climate Change emphasizes the importance of improving the electrification rates to reducing GHG emissions. Using the five models participating in Energy Modeling Forum 35 Japan Model Intercomparison project (JMIP), we focused on the demand-side decarbonization and analyzed the final energy composition required to achieve 80% reductions in GHGs by 2050 in Japan. The model results show that the electricity share in final energy use (electrification rate) needs to reach 37–66% in 2050 (26% in 2010) to achieve the emissions reduction of 80%. The electrification rate increases mainly due to switching from fossil fuel end-use technologies (i.e. oil water heater, oil stove and combustion-engine vehicles) to electricity end-use technologies (i.e. heat pump water heater and electric vehicles). The electricity consumption in 2050 other than AIM/Hub ranged between 840 and 1260 TWh (AIM/Hub: 1950TWh), which is comparable to the level seen in the last 10 years (950–1035 TWh). The pace at which electrification rate must be increased is a challenge. The model results suggest to increase the electrification pace to 0.46–1.58%/yr from 2030 to 2050. Neither the past electrification pace (0.30%/year from 1990 to 2010) nor the outlook of the Ministry of Economy, Trade and Industry (0.15%/year from 2010 to 2030) is enough to reach the suggested electrification rates in 2050. Therefore, more concrete measures to accelerate dissemination of electricity end-use technologies across all sectors need to be established

Early retirement of power plants in climate mitigation scenarios

International efforts to avoid dangerous climate change aim for large and rapid reductions of fossil fuel CO2 emissions worldwide, including nearly complete decarbonization of the electric power sector. However, achieving such rapid reductions may depend on early retirement of coal- and natural gas-fired power plants. Here, we analyze future fossil fuel electricity demand in 171 energy-emissions scenarios from Integrated Assessment Models (IAMs), evaluating the implicit retirements and/or reduced operation of generating infrastructure. Although IAMs calculate retirements endogenously, the structure and methods of each model differ; we use a standard approach to infer retirements in outputs from all six major IAMs and—unlike the IAMs themselves—we begin with the age distribution and region-specific operating capacities of the existing power fleet. We find that coal-fired power plants in scenarios consistent with international climate targets (i.e. keeping global warming well-below 2 °C or 1.5 °C) retire one to three decades earlier than historically has been the case. If plants are built to meet projected fossil electricity demand and instead allowed to operate at the level and over the lifetimes they have historically, the roughly 200 Gt CO2 of additional emissions this century would be incompatible with keeping global warming well-below 2 °C. Thus, ambitious climate mitigation scenarios entail drastic, and perhaps un-appreciated, changes in the operating and/or retirement schedules of power infrastructure

Behavior of vascular resistance undergoing various pressure insufflation and perfusion on decellularized lungs

Bioengineering of functional lung tissue by using whole lung scaffolds has been proposed as a potential alternative for patients awaiting lung transplant. Previous studies have demonstrated that vascular resistance (Rv) could be altered to optimize the process of obtaining suitable lung scaffolds. Therefore, this work was aimed at determining how lung inflation (tracheal pressure) and perfusion (pulmonary arterial pressure) affect vascular resistance. This study was carried out using the lungs excised from 5 healthy male Sprague-Dawley rats. The trachea was cannulated and connected to a continuous positive airway pressure (CPAP) device to provide a tracheal pressure ranging from 0 to 15 cmH(2)O. The pulmonary artery was cannulated and connected to a controlled perfusion system with continuous pressure (gravimetric level) ranging from 5 to 30 cmH(2)O. Effective Rv was calculated by ratio of pulmonary artery pressure (P-PA) by pulmonary artery flow (V'(PA)). Rv in the decellularized lungs scaffolds decreased at increasing V'(PA), stabilizing at a pulmonary arterial pressure greater than 20 cmH(2)O. On the other hand, CPAP had no influence on vascular resistance in the lung scaffolds after being subjected to pulmonary artery pressure of 5 cmH(2)O. In conclusion, compared to positive airway pressure, arterial lung pressure markedly influences the mechanics of vascular resistance in decellularized lungs. (C) 2016 Elsevier Ltd. All rights reserved

Air quality co-benefits from climate mitigation for human health in South Korea

Climate change mitigation efforts to reduce greenhouse gas (GHG) emissions have associated costs, but there are also potential benefits from improved air quality, such as public health improvements and the associated cost savings. A multidisciplinary modeling approach can better assess the co-benefits from climate mitigation for human health and provide a justifiable basis for establishment of adequate climate change mitigation policies and public health actions. An integrated research framework was adopted by combining a computable general equilibrium model, an air quality model, and a health impact assessment model, to explore the long-term economic impacts of climate change mitigation in South Korea through 2050. Mitigation costs were further compared with health-related economic benefits under different socioeconomic and climate change mitigation scenarios. Achieving ambitious targets (i.e., stabilization of the radiative forcing level at 3.4 W/m2) would cost 1.3-8.5 billion USD in 2050, depending on varying carbon prices from different integrated assessment models. By contrast, achieving these same targets would reduce costs by 23 billion USD from the valuation of avoided premature mortality, 0.14 billion USD from health expenditures, and 0.38 billion USD from reduced lost work hours, demonstrating that health benefits alone noticeably offset the costs of cutting GHG emissions in South Korea

Climate Change Effects on Agriculture: Economic Responses to Biophysical Shocks

Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(sup 2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change

Reducing stranded assets through early action in the Indian power sector

Cost-effective achievement of the Paris Agreement's long-term goals requires the unanimous phase-out of coal power generation by mid-century. However, continued investments in coal power plants will make this transition difficult. India is one of the major countries with significant under construction and planned increase in coal power capacity. To ascertain the likelihood and consequences of the continued expansion of coal power for India's future mitigation options, we use harmonised scenario results from national and global models along with projections from various government reports. Both these approaches estimate that coal capacity is expected to increase until 2030, along with rapid developments in wind and solar power. However, coal capacity stranding of the order of 133–237 GW needs to occur after 2030 if India were to pursue an ambitious climate policy in line with a well-below 2 °C target. Earlier policy strengthening starting after 2020 can reduce stranded assets (14–159 GW) but brings with it political economy and renewable expansion challenges. We conclude that a policy limiting coal plants to those under construction combined with higher solar targets could be politically feasible, prevent significant stranded capacity, and allow higher mitigation ambition in the future