Suitability hotspots
The most suitable areas under current climate conditions were projected to host up to 64 of the 110 study species, with 11.9% of the total study area (446,686 km2) projected to be suitable for at least 30% of the study species (i.e., 33 species; Figure 4). We detected four contiguous hotspots in all climate models: the lower Himalayas of north and northeast India, northeastern Pakistan, Nepal, northern Myanmar, and Bangladesh; the Andaman and Nicobar islands and southernmost coast of Myanmar; Sri Lanka, covering the entirety of the island; and south India, in the Western Ghats and along the coasts of central and southern Maharashtra, Karnataka, and Kerala, and fragmented regions of southern Karnataka and southern Tamil Nadu, extending to the southern Nilgiris and Coromandel coast of Tamil Nadu. Additional smaller hotspots appear in the Ballari-Vijayapura-Hubli region of Karnataka, India, an area characterised by unique geography and isolated geology and climate; the highlands west of the Indus valley in northern Pakistan and eastern Afghanistan; and regions including and immediately north of Gir National Park, southern Gujarat, India (Figure 4).
Most of these hotspots were projected to remain climatically suitable for many species by the mid-21st century in all scenarios, although their extent was generally reduced, particularly in the lower Himalayas and the Western Ghats hotspots, and projections suggested northward shifts in the Himalayan regions (Figure 4). In northern India and northern Pakistan, projected changes reduced contiguity in projected suitability hotspots (particularly under the CanESM5 scenarios). In the Western Ghats, declines particularly affected central Maharashtra and Tamil Nadu. Additionally, the small distinct hotspots in Ballari-Vijayapura-Hubli were projected to disappear, while hotspots west of the Indus valley and north of Gir were projected to expand (Figure 4). Although both climate change models predicted similar changes, under both HadGEM3 scenarios a marked northward increase in suitable area in southern Myanmar was projected. Analysis of model certainty showed a moderate degree of uncertainty around the projected suitability hotspots in all scenarios, combined with some areas of high certainty of suitability in the Himalayas and northeastern India, and in southern India and central-southwestern Sri Lanka (Supplementary Material 3).