Biodiversity variations and functional changes in the terrestrial ecosystem due to the ongoing climate change are going to affect the ecological connectivity between land and sea, however modelling these teleconnections remains a major challenge for future climate scenarios. Yet the geological record provides an archive of how these interactions operated during past climatic crises providing an insight for whole-ecosystem models. During past global warming periods vegetation changes impacted the hydrological cycle by increasing nutrient and sediment input in the oceans leading to eutrophication, siltation stress or oxygen depletion in marine environments. Still, the intensity, processes, and timing of the mechanisms linking terrestrial and marine ecosystems remain poorly understood. To understand the ecological connectivity between land and sea, we are looking at past climatic perturbations with a quantitative approach including vegetation data from plant microfossils, marine organisms (foraminifers, ostracods, conodonts, molluscs), and geochemical-mineralogical proxies (main and trace element analysis, stable carbon isotopes, clay minerals, biomarkers). To explore land-to-sea ecological connectivity during times of major climate change, we are targeting the Early Triassic period when plant life underwent revolutionary changes after the biggest mass extinction, the End Permian mass extinction. This recovery period was punctuated by the Late Smithian Thermal Maximum and Smithian–Spathian boundary event representing the final phase of climate and carbon cycle perturbation, and a tipping point in the recovery of plants before forested ecosystems re-emerged. To expand the knowledge on these biotic events, we target Early Triassic shallow marine sedimentary successions from Croatia, Hungary, and China that will be investigated to establish the land-to-sea correlation of biotic events. The paleogeographic distribution of the study area will also allow to explore latitudinal variability in such correlation. This integrated, holistic approach may help understanding how modern ecosystems will respond to environmental and ecological changes induced by global warming.