Triassic climates – State of the art and perspectives

The climate of the Triassic period was characterized by a non-zonal pattern, dictated by a strong global monsoon system with effects that are most evident in the Tethys realm. This strong monsoonal regime is related to the aggregation of the Pangaean supercontinent, which by Triassic time was already completed. Climate oscillations existed within this framework. The harsh hot-house climatic conditions that characterized the Late Permian, and perhaps precipitated the end-Permian mass extinction, were probably maintained during the Early Triassic and may account for the impoverished, but distinctive, faunal and floral Lower Triassic associations. Although metazoan reef builders were probably the most affected group, carbonate production remained high at least in the western Tethys realm. The Middle Triassic was characterized locally by humid episodes, although their geographical distribution has yet to be clarified. The Carnian Pluvial Event, marks an episode of increased rainfall documented worldwide, was the most distinctive climate change within the Triassic. Different hypotheses have been proposed for its causes: changes of atmospheric or ocean circulation driven by plate tectonics; a peak of the global monsoon due to maximum continent aggregation; or triggering by the eruption of a large igneous province. Subsequently, the late Carnian and Norian seem to have been climatically stable, although minor climatic changes have recently been described even from this time period. Finally, the end-Triassic extinction event is also associated with climate change, specifically warming and increased rainfall, but this evidence comes mostly from the northern parts of the Central Atlantic Magmatic Province, and the global pattern of climate change at the Triassic/Jurassic boundary has still to be resolved. Many facets of Triassic climate are intriguing and deserve further research. However, palaeoclimate studies on the Triassic have so far been carried out only locally with different proxies. Those proxies will require inter-calibration, in order to depict correctly the temporal and geographical patterns of Triassic climate.