The Late Permian mass extinction was not only the most catastrophic known loss of biodiversity, but was followed by unusually prolonged recovery through the Early Triassic. Opinion has been divided on whether delayed recovery was a legacy of especially profound ecological disruption, or due to additional environmental perturbations. New records from the Sydney Basin in southeastern Australia now reveal five successive Late Permian and Early Triassic spikes of unusually high atmospheric CO2 and profound chemical weathering. These successive atmospheric CO2 greenhouse crises coincided with unusually warm and wet paleoclimates for a paleolatitude of 61°S. Successive transient greenhouse crises punctuated long-term, cool, dry, and low-CO2 conditions, and may account for the persistence of low diversity and small size in Early Triassic plants and animals.