The greening of the Himalayas and Tibetan Plateau under climate change

Abstract

The possible disruption of climate change (CC) on the ecological, economic and social segments of human interest has made this phenomenon a major issue over the last couple of decades. Mountains are fragile ecosystems, projected to endure a higher impact from the increased warming. This study presents modelled CC projections with respect to the suitability for the growth of nine near-treeline plant species of the Himalayas and Tibetan Plateau through niche modelling technique using CLIMEX and estimates their potential future distribution and the extent of greening in the region. Two global climate models, CSIRO-MK 3.0 (CS) and MIROCHH (MR) were used under IPCC A1B and A2 emission scenarios for the year 2050 and 2100. The results indicate that climatic suitability of the nine species expands towards higher elevations into areas that are currently unsuitable while currently suitable areas in many regions become climatically unsuitable in the future. The total climatically suitable area for the nine species at current time is around 1.09 million km2, with an additional 0.68 and 0.35 million km2 becoming suitable by 2050 and 2100 respectively. High elevation belts, especially those lying above 3500 m, will see more climatically suitable areas for the nine species in the future. Cold stress is the main factor limiting current distribution and its decrease will affect the overall expansion of climatic suitability in the region. Impacts on nature conservation and water and food security could be expected from such shift of climatic suitability in the region.