GC053-0002
How much remaining allowable warming is allowed for the 2 ℃ and 1.5 ℃ climate targets?
Thursday, 10 December 2020
Poster
Xuanming Su, JAMSTEC Japan Agency for Marine-Earth Science and Technology, Research Institute for Global Change (RIGC) / Research Center for Environmental Modeling and Application (CEMA) / Earth System Model Development and Application Group (ESM-DAG), Kanagawa, Japan, Katsumasa Tanaka, LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette, France; NIES National Institute for Environmental Studies, Tsukuba, Japan, Kaoru Tachiiri, Japan Agency for Marine-Earth, Yokohama, Japan, Michio Watanabe, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan and Michio Kawamiya, JAMSTEC Japan Agency for Marine-Earth Science and Technology, Kanagawa, Japan
Abstract:
The allowable warming is defined as the temperature that can be allowed to increase during achieving the climate targets, set in Paris Agreement, that is, to limit the global average temperature to well below 2 ℃ and to pursue efforts to avoid 1.5 ℃ above pre-industrial level. In this study, we applied a normalized marginal method to the Simple Climate Model for Optimization version 2 (SCM4OPT v2.0), to quantify the allowable warmings at regional and sectoral levels for the 2 ℃ and 1.5 ℃ climate targets. Based on the most up-to-date emission datasets, we first calculated two groups of warming effects, including 1) temperature increase resulting from emissions of historical period of 1850-2016 (committed climate impacts), and 2) temperature increase resulting from emissions of the full evaluated period of 1850-2100 (gross temperature increases). Then we subtracted the committed climate impacts from the gross temperature increases, to obtain the allowable warmings.
The preliminary results show that, the remaining allowable warmings for the 2℃ and 1.5 ℃ are 0.68±0.11 ℃ and 0.30±0.13 ℃, respectively, based on the scenarios analysis; For the remaining allowable warmings, the CO2, CH4 and NH3 are major emission sources, and the agriculture, energy, industry, surface transport and housing are main sectoral sources; China and the Middle East and North Africa (MEA) are main contributors to the remaining allowable warmings for both the 2 ℃ and 1.5 ℃, while the USA, sub-Saharan Africa (AFR) and other Asia (OAS) are main contributors for the 2 ℃, and their warming effects are substantially reduced for the 1.5 ℃. Our results provide a robust quantification of temperature attributions at regional and sectoral levels.
