Japan Geoscience Union Meeting 2018

Presentation information

[EE] Evening Poster

H (Human Geosciences) » H-CG Complex & General

[H-CG21] Climate-human system interaction

Mon. May 21, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Kaoru Tachiiri(Japan Agency for Marine-Earth Science and Technology), Tokuta Yokohata(National Institute for Environmental Studies), Katsumasa Tanaka(国立環境研究所, 共同), KIYOSHI TAKAHASHI(National Institute for Environmental Studies)

[HCG21-P04] Social Cost of Carbon (SCC) under Different Socioeconomic Development Patterns

*Xuanming Su1, Shinichiro FUJIMORI2, Kaoru Tachiiri1, Hancheng DAI3, Katsumasa Tanaka2, Kiyoshi TAKAHASHI2, Hideo Shiogama2 (1.Japan Agency for Marine-Earth Science and Technology, 2.National Institute for Environmental Studies, 3.Peking University)

Keywords:Social cost of carbon, Climate change, SSP scenarios, SCM4OPT

The social cost of carbon (SCC) is an important economic concept used to measure the economic cost caused by an additional ton of carbon dioxide (CO2) emissions or its equivalent. Nordhaus (2011) defines it as “the change in the discounted value of the utility of consumption denominated in terms of current consumption per unit of additional emissions”. There are a wide range of uncertainties regarding the social cost of carbon. However, the focus is usually placed on limited sources of uncertainty in the socioeconomic or physical climate aspects for existing studies. Using a stochastic version of the Simple Climate Model for Optimization (SCM4OPT) (Su et al., 2017; 2018), this study aims to estimate the SCC under different socioeconomic development patterns.

A preliminary output for this study can be seen in Figure 1. First, different socioeconomic development levels represented by the 5 SSP scenarios cause a wide range of SCC in future. In 2020, the lowest SCC can be found in SSP 1 with a mean value of about 62 USD(2005)/tCO2, and the highest can be found in SSP 5 with 71 USD(2005)/tCO2. However, by the end of this century, the SCC of SSP 1 increases to about 448 USD(2005)/tCO2, while SCC for SSP5 is up to 973 USD(2005)/tCO2. On the other hand, uncertainties resulting from human current understanding of climate system also cause a large uncertainty regarding SCC, as shown in the area for each SSP scenario. For example, a range of 315-686 USD(2005)/tCO2 is found in 2100 regarding SSP 1, and 743-1530 USD(2005)/tCO2 for SSP 5. Both socioeconomic assumptions and biophysical climate system can cause a wide range of uncertainties with respect to the SCC. A comprehensive consideration of the SCC uncertainties exist in various sources is important in the assessment of climate change policy.

This is an ongoing study and following two issues also need to be considered in future: 1) Current biophysical uncertainties in SCM4OPT are represented by a relative old version of model comparison of GCM simulations and we will update them based on CMIP6; 2) We will make a sensitivity analysis to distinguish the impacts resulting from different specific sources.

Figure 1: Social cost of carbon under uncertainty. The ranges between the lower and upper areas show the likely probabilities (i.e., the 17th and 83rd percentiles).

References

Fujimori, S., T. Hasegawa, T. Masui, K. Takahashi, D. S. Herran, H. Dai, Y. Hijioka, and M. Kainuma (2017), SSP3: AIM implementation of Shared Socioeconomic Pathways, Global Environ. Change, 42, 268–283. https://doi.org/10.1016/j.gloenvcha.2016.06.009.

Nordhaus, W.D. (2011). Estimates of the social cost of carbon: background and results from the RICE-2011 model. http://www.econ.yale.edu/~nordhaus/homepage/ documents/CFDP1826.pdf.

Su, X., Takahashi, K., Fujimori, S., Hasegawa, T., Tanaka, K., Kato, E., Shiogama, H., Masui, T. and Emori, S. (2017), Emission pathways to achieve 2.0°C and 1.5°C climate targets. Earth's Future, 5: 592–604. https://doi.org/10.1002/2016EF000492.

Su, X., Shiogama, H., Tanaka, K., Fujimori, S., Hasegawa, T., Hijioka, Y., … Liu, J. (2018). How do climate-related uncertainties influence 2 and 1.5 °C pathways? Sustainability Science. https://doi.org/10.1007/s11625-017-0525-2.