Efficacy of the global protected area network is threatened by disappearing climates and potential transboundary range shifts

Protected areas are essential to conserving biodiversity, yet changing climatic conditions challenge their efficacy. For example, novel and disappearing climates within the protected area network indicate that extant species may not have suitable climate in protected areas in the future. Further, potential transboundary range shifts, those that involve movement from one country to another, are also challenging because physical (e.g. fencing) and non-physical barriers (e.g. contrasting conservation policies) may impede climate-induced movements. Through the lens of climate analogs, we examined disappearing and novel climates within the global terrestrial protected area network and the potential for transboundary range shifts among protected areas under global warming 2 degrees C above preindustrial levels. We found that globally, climates in 24% of protected lands will no longer be protected within a 500 km radius of their focal location (indicating disappearing climates within the protected area network), while 36% of protected lands will gain climates not previously protected (indicating novel climates within the protected area network). Further, we found that potential transboundary range shifts are widespread but variable; for example, 23% of protected climates in Europe and >50% of protected climates in Africa under climate change are located in a different country than the focal protected areas. As the global conservation community actively deliberates conservation frameworks (e.g. 30% by 2030), our study offers insights to reduce the prevalence of novel and disappearing climates within the global protected area network via strategic conservation actions and underscores the importance of setting and accommodating targets and strategies that transcend national boundaries.