Summary:  Climate change is driving broad-scale redistribution of species on the Earth, and may accelerate in the coming decades, potentially undermining the effectiveness of protected areas (PAs) for species conservation. To assess exposure of global PAs to future climate change risks, we developed a new climate change velocity measure to quantify the magnitude and spatial pattern of climate zone shifts for global terrestrial PAs under alternative future climate scenarios. The “climate zone velocity” represents the potential minimum velocity of species movement required to track climate zone changes over time. It has high spatial resolution (1-km) and is derived from topographic paths to capture topographic effects on habitat conditions. Climate zones are defined based on Köppen-Geiger climate classes, which integrate biological information and incorporate multiple climatic indicators. We find that 20%-38% of global protected land could undergo pronounced climate zone shifts at accelerating rates during the remainder of this century. Moreover, protected lands are experiencing heightened climate change exposure from the novel (3.7%-8.3% of global protected land) and disappearing (3.0%-6.6%) climates, shifts of climates outside PA networks (3.8%-7.6%), and transition to human-dominated land use (2.8-5.7%). PAs located across arid (B) and boreal (D) climate zones, in mid-latitudes of North America, Europe, Russia, and Africa, and those with strict management categories (IUCN category I-II), are facing more rapid and substantial changes. Relationships with PA attributes, such as species richness, terrain ruggedness, and human footprint level, indicate that small, high-elevation PAs with complex topography and high species richness could experience more increased vulnerability. Taken together, these results suggest that strategic and adaptive conservation planning that explicitly considers climate shifts should be a priority for meeting conservation goals.