title: Downscaling Global Emissions and Its Implications Derived from Climate Model Experiments.
abstract: In climate change research, future scenarios of greenhouse gas and air pollutant emissions generated by integrated assessment models (IAMs) are used in climate models (CMs) and earth system models to analyze future interactions and feedback between human activities and climate. However, the spatial resolutions of IAMs and CMs differ. IAMs usually disaggregate the world into 10-30 aggregated regions, whereas CMs require a grid-based spatial resolution. Therefore, downscaling emissions data from IAMs into a finer scale is necessary to input the emissions into CMs. In this study, we examined whether differences in downscaling methods significantly affect climate variables such as temperature and precipitation. We tested two downscaling methods using the same regionally aggregated sulfur emissions scenario obtained from the Asian-Pacific Integrated Model/Computable General Equilibrium (AIM/CGE) model. The downscaled emissions were fed into the Model for Interdisciplinary Research on Climate (MIROC). One of the methods assumed a strong convergence of national emissions intensity (e.g., emissions per gross domestic product), while the other was based on inertia (i.e., the base-year remained unchanged). The emissions intensities in the downscaled spatial emissions generated from the two methods markedly differed, whereas the emissions densities (emissions per area) were similar. We investigated whether the climate change projections of temperature and precipitation would significantly differ between the two methods by applying a field significance test, and found little evidence of a significant difference between the two methods. Moreover, there was no clear evidence of a difference between the climate simulations based on these two downscaling methods.
authors.affiliation: Center for Social and Environmental Systems Research, National Institute for Environmental Studies (NIES), 16-2, Onogawa, Tsukuba, Japan.
authors.forename: Shinichiro
authors.identifier: http://orcid.org/0000-0001-7897-1796
authors.initials: S
authors.lastname: Fujimori
authors.affiliation: Department of Integrated Climate Change Projection Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Abe
authors.affiliation: College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Japan.
authors.forename: Tsuguki
authors.initials: T
authors.lastname: Kinoshita
authors.affiliation: Center for Social and Environmental Systems Research, National Institute for Environmental Studies (NIES), 16-2, Onogawa, Tsukuba, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hasegawa
authors.affiliation: Meteorological Research Institute, 1-1, Nagamine, Tsukuba, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kawase
authors.affiliation: Mizuho Information & Research Institute, Inc., 2-3 Kanda-Nishikicho, Chiyoda-ku, Japan.
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Kushida
authors.affiliation: Center for Social and Environmental Systems Research, National Institute for Environmental Studies (NIES), 16-2, Onogawa, Tsukuba, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Masui
authors.affiliation: Mizuho Information & Research Institute, Inc., 2-3 Kanda-Nishikicho, Chiyoda-ku, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Oka
authors.affiliation: Center for Global Environmental Research, National Institute for Environmental Studies (NIES), 16-2, Onogawa, Tsukuba, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Shiogama
authors.affiliation: Center for Social and Environmental Systems Research, National Institute for Environmental Studies (NIES), 16-2, Onogawa, Tsukuba, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Integrated Climate Change Projection Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tatebe
authors.affiliation: Mizuho Information & Research Institute, Inc., 2-3 Kanda-Nishikicho, Chiyoda-ku, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D057231:Climate Change; D003198:Computer Simulation; D003247:Conservation of Natural Resources / Q000191:economics / Q000379:methods*; D008962:Models, Theoretical; D011891:Rain; D013696:Temperature; D001335:Vehicle Emissions / Q000517:prevention & control*
chemical_list: D001335:Vehicle Emissions