“…The changes in the areas of climate zones indicate the expansion or shrinkage of the spatial extent of the Earth's macro-climatic conditions, potentially implying the retreat or spread of biomes as well as threats of species range contraction or opportunities for range expansion. One of the most pronounced changes in the area of climate zones during the past century is the shrinkage of the polar climate zone with the size equivalent to 0.50-0.98% of the Earth's total land area (Beck, Grieser, Kottek, et al, 2005;Belda et al, 2014;Chan & Wu, 2015;Fraedrich et al, 2001;Kalvová et al, 2003;Rohli, Joyner, Reynolds, Shaw, et al, 2015). The other dominating area change since the 1900s is the area expansion of the arid climate zone, which is equivalent to 0.68-1.51% of the Earth's total land area, reported in recent studies that used KGC criteria to define the arid climate zone (Beck, Grieser, Kottek, et al, 2005;Chan & Wu, 2015;Rohli, Joyner, Reynolds, Shaw, et al, 2015).…”