Why can climate change make it harder for species to survive in their usual habitats?

Climate change challenges the survival of species by altering the environmental conditions to which they have historically adapted. Because these changes often occur more rapidly than natural climate variability, many species struggle to keep pace with the shifting requirements of their habitats.1

Key factors that make survival difficult include:

• Geographic Range Shifts: Many species are forced to migrate toward cooler regions, such as higher latitudes or mountaintops. Species with limited mobility or those living on isolated mountaintops may find their "climate envelope"—the range of conditions they need to survive—shrinking until it disappears entirely, leaving them with nowhere to go.2
• Phenological Mismatches: Warming temperatures alter the timing of seasonal events like breeding, migration, and flowering. This can create dangerous mismatches; for example, migratory birds may arrive at breeding grounds too late to feed their young if the peak emergence of their insect prey has already passed.21
• Habitat Loss and Degradation: Rising sea levels threaten coastal ecosystems like wetlands and mangroves, while warming waters cause coral bleaching, destroying vital habitats.1
• Combined Stresses: Climate change often compounds existing threats like habitat fragmentation, pollution, and the spread of infectious diseases, making it significantly harder for species to persist.21