Prof. Qigang Wu and I detected and attributed historical changes in the Köppen Climate regime (Chan and Wu, 2015). We found significant anthropogenically induced changes in each of the five major Köppen Climate regimes since the 1950s. Moreover, 5.7% of the Earth's land surface has experienced changes in climate regimes. This study is highlighted as one of the key climate science research advances in 2015 (news). We also analyzed the emergent time of significant changes in the Köppen Climate regime over China under different emission scenarios (Chan et al., 2016).

Fig. 1 Detection and attribution of changes in major Köppen Climate Regime. Shown bars are trends from 1950-1998. Regimes are A: Tropical Climate, B: Arid Climate, C: Temperate climate, D: Continental climate, and E: Polar climate. Changes are depicted by three aspects: Area, Elevation ( Elv), and Absolute Latitude ( Lat), representing the expansion/shrinkage and shifts of climate types. For each index, individual bars are observation based on University of Delaware dataset (black), CMIP5 historical all forcing experiment (yellow), historical GHG forcing experiment (red), and historical natural forcing experiment (blue). Error bars are the one sigma uncertainty of internal variability estimated from 225 CMIP5 pi-control samples. Diamonds denote that simulated trends are significantly different from observations (p<0.05).

  1. Chan, D., Wu, Q., Jiang, G., & Dai, X. (2016). Projected shifts in Köppen climate zones over China and their temporal evolution in CMIP5 multi-model simulations. Advances in Atmospheric Sciences, 3(33), 283-293. link, pdf
  2. Chan, D., & Wu, Q. (2015). Significant anthropogenic-induced changes of climate classes since 1950. Scientific Reports. 5. 13487. Doi: 10.1038/srep13487. link, pdf, news