Atlas of Climate Change: Responsibility and Obligation of Human Society

This chapter introduces the data and methods utilized in the computation in the following chapters, as well as the experimental designs of numerical simulations in Chaps. 4, 5, and 6.

Sections 2.1 and 2.2 present the evaluations of CMIP5 models in reproducing the historical climate change and projections of future climate change under three scenarios of RCP2.6, RCP4.5, and RCP8.5 in terms of surface air temperature and precipitation over the globe and China; Sect. 2.3 presents the atmospheric circulations over the Asia-Pacific region in terms of the East Asian Summer Monsoon (EASM) (Guo, Acta Geograph Sin 38(3):208–217, 1983), Western Pacific Subtropical High (WPSH) area and strength (Liu et al., J Appl Meteorol Sci 23(4):414–423, 2012), Arctic Oscillation (AO) (Thompson and Wallace, Geophys Res Lett 25:1297–1300, 1998), and Siberian High (SH) (Wu and Wang, Geophys Res Lett 29(19):1897, 2002); and Sect. 2.4 presents the climate extremes in China. The analyzed climate extreme elements include surface air maximum temperature and surface air minimum temperature, consecutive dry days – maximum number of consecutive days with less than 1 mm of precipitation (CDD) – and simple daily precipitation intensity (SDII) (Frisch et al., Clim Res 19:193–212, 2002). The historical climatology is set to long-term mean over 1986–2005. In projection, the uncertainty range is given described by one inter-model standard deviation.

In Sect. 2.5, the simulation ability and future change of the sea surface temperature (SST) in the South China Sea (SCS) are analyzed by using 21 CMIP5 models. Finally, Sect. 2.6 provides the simulated historical Northern Hemisphere sea ice concentration (SIC) and sea ice area (SIA) by 22 coupled climate models from CMIP5. The SIA is defined as the total area with at least 15 % sea ice in Northern Hemisphere. The projected future changes of Northern Hemisphere SIC and SIA under RCP4.5 and RCP8.5 are also shown.

In this chapter, the results of three different multi-model ensemble mean methods are compared. In Sect. 3.1, the global mean surface air temperature and precipitation from multi-model weighted mean and equal-weighted mean are compared. The weight is given according to the correlation coefficients and relative bias between model and observation. The results from the multi-model weighted mean and the equal-weighted mean show no significant difference. In Sect. 3.2, the surface air temperature and precipitation in China from multi-model equal-weighted mean and Bayesian model averaging (BMA) method are compared. BMA is a multi-model ensemble method which considered each model’s posterior distributions and then weighted by posterior model probability. In our calculation, the training of BMA is based on observational data (derived from CRUTS 3.21) for the period of 1961–1990. The multi-model ensemble mean in Sects. 3.1 and 3.2 is calculated based on 22 CMIP5 models described in Chap. 1.

In Sect. 3.3, the global mean surface air temperature and precipitation simulated by equal-weighted ensemble mean of 8 (analyzed in another Atlas (Dong WJ et al, The atlas of climate change: based on SEAP-CMIP5. Springer. doi:10.​1007/​978-3-642-31773-6, 2013)) and 22 CMIP5 models are compared with the results from IPCC AR5 (Collins M et al., Long-term climate change: projections, commitments and irreversibility. In: Stocker TF et al., (eds) Climate change 2013: the physical science basis. Contribution of Working Group I to the Fifth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, 2013; Flato G et al., Evaluation of climate models. In: Stocker TF et al., (eds) Climate change 2013: the physical science basis. Contribution of Working Group I to the Fifth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge/New York, 2013). The ensemble of the 22 CMIP5 models show better performance than that of 8 models and is similar with that of IPCC AR5.

This chapter shows the results of attribution experiments which assess the contributions of historical anthropogenic carbon emissions to global warming from developed and developing countries. These numerical experiments are performed based on NCAR/CESM1_0_2 model for the period of 1850–2011.

This chapter shows the results of the impacts of anthropogenic sulfur emissions from Annex I and non-Annex I countries for the period of 1850–2005. These numerical experiments named Both, Ann1, Non1, and Zero are performed based on NCAR/CESM1_0_2 model. The analyzed climate elements involve aerosol concentration, aerosol optical depth, air temperature, precipitation, cloud, solar flux, sea level pressure, zonal circulation, sea ice extent, etc.

This chapter shows the results of attribution experiments which assess the influences of transferred carbon emissions along with international trade on the historical responsibility of developed/developing countries and on the potential mitigation ability of the Kyoto Protocol. These numerical experiments are performed based on NCAR/CESM1_0_2 model for the period of 1990–2005.