Research into projected climate and environmental changes across the Tibetan Plateau in the 21st century is reviewed. Climate and environmental factors involved include surface air temperature, rainfall, extreme weather and climate events, frozen soil, snow cover, glaciers, runoff, and vegetation. Projections are mainly from climate model simulations under the Special Report on Emissions Scenarios (SRES) and Representative Concentration Pathway (RCP) as well as from physical statistical models. In the future, surface air temperature across the Tibetan Plateau will rise and this rise will become more rapid in the late 21st century. Generally, in that century, rainfall, extreme weather and climate events, and active layer depth of frozen soil across the plateau will increase. However, near-surface permafrost area, snow-covered days, snow water equivalent, and glacier coverage and amount will decrease. Changes of runoff across the plateau show complexity during the 21st century. Runoff varies greatly by drainage basin, with some basins showing increases and others decreases. Vegetation is sensitive and fragile in response to the climate change. In the middle and late century, growing season will lengthen, evergreen forest/woodland will replace alpine tundra on the southern and eastern plateau, and scrub vegetation will expand and invade the alpine steppe region. Based on existing research, we comprehensively integrate all these projected climate and environmental factors and present their potential changing ranges in the middle (2030-2050) and late (2080-2100) portions of the 21st century.