The region is physiographically diverse and ecologically rich in natural and crop-related biodiversity. Exploitation of natural resources associated with rapid urbanization, industrialization, and economic development has led to increasing pollution, land degradation, and other environmental problems.
Climate change represents a further stress.
Over the long period of human occupation in the region, human use systems have developed some resilience to a range of environmental stresses. However, it is uncertain whether such resilience can continue in the face of rapid socioeconomic development, increasing population, and projected changes in climate. Over the past 100 years, mean surface temperatures across the region have increased in the range of 0.3 0.8 C. No long-term trend in mean rainfall has been discernible over that period, although many countries have shown a decreasing trend in the past three decades. Ecological Systems Substantial elevational shifts of ecosystems in the mountains and uplands of Tropical Asia are projected. At high elevations, weedy species can be expected to displace tree species, although the rates of vegetation change could be slow and constrained by increased erosion in the Greater Himalayas.