Masahiro Sugiyama 교수

Precipitation extreme changes are often assumed to scale with, or are constrained by, the change in atmospheric moisture content. Studies have generally confirmed the scaling based on moisture content for the midlatitudes but identified deviations for the tropics. In fact half of the twelve selected Intergovernmental Panel on Climate Change (IPCC) models exhibit increases faster than the climatological-mean precipitable water change for high percentiles of tropical daily precipitation, albeit wi

Japan is the sixth largest greenhouse gas emitter in 2016 and plays an important role to attain the long-term climate goals of the Paris Agreement. One of the key policy issues in Japan's energy and environmental policy arena is the energy system transition to achieve 80% emissions reduction in 2050, a current policy goal set in 2016. To contribute to the ongoing policy debate, this paper focuses on energy-related CO2 emissions and analyzes such decarbonization scenarios that are consistent with

Abstract The moisture mode in a simplified version of the quasi-equilibrium tropical circulation model (QTCM) of Neelin and Zeng is analyzed. Perturbation expansion based on the ratio of temperature tendency to adiabatic cooling simplifies the system and dispersion relationship. The weak temperature gradient (WTG) approximation of Sobel, Nilsson, and Polvani naturally emerges as the dynamical balance of the moisture mode. The condition of the expansion can be phrased in terms of the nondimension

The online version contains supplementary material available at 10.1007/s11625-021-00913-2.

Climate engineering has received increasing attention, but its discussion has remained on the sidelines of mainstream climate policy. The policy relevance of this previously exotic option is poised to rise because of the gap between the temperature goals of the Paris Agreement and slow global mitigation efforts. It is therefore crucial to understand the risks and benefits of the proposed schemes, and the social implications of policy choices. Assessment of the risks and benefits of solar geoengi

Solar radiation management (SRM) is a controversial technological proposal to deliberately cool the Earth for addressing climate change. Because of great concerns over global consequences of SRM deployment, an inclusive and global conversation is considered necessary for the governance of SRM. However, public perception research on SRM to date has been mostly limited to the Global North or Western democracy. Because social acceptability is crucial for SRM governance, such research must also enco

The core of the digital transition is the representation of all kinds of real-world entities and processes and an increasing number of cognitive processes by digital information and algorithms on computers. These allow for seemingly unlimited storage, operation, retrieval, and transmission capacities that make digital tools economically available for all domains of society and empower human action, particularly combined with real-world interfaces such as displays, robots, sensors, 3D printers, e

Abstract Numerical calculations of a simplified quasi-equilibrium tropical circulation model (QTCM) on the equatorial β plane have been performed to explore the nonlinear regime of the moisture mode. Sensitivity tests have examined the effects of nonlinear advection and nonlinear wind-induced surface heat exchange (WISHE). Starting from a spatially homogeneous radiative–convective equilibrium with some background gustiness, the model develops quasi-stationary moisture modes, as expected from lin

To improve the estimate of economic costs of future sea-level rise associated with global climate change, this report generalizes the sea-level rise cost function originally proposed by Fankhauser, and applies it to a new database on coastal vulnerability developed as part of the Dynamic Interactive Vulnerability Assessment (DIVA) tool.\nAn analytic expression for the generalized sea-level rise cost function is obtained to explore the effect of various spatial distributions of capital and nonlin