Data for "Carryover" or "Overshoot"? The global evidence of satellite-derived carbon-water coupling

Carbon-water coupling (CWC) provides a fundamental metric for assessing the synchrony between carbon uptake and water use in terrestrial ecosystems and plays a critical role in shaping land-atmosphere interactions. With intensifying climate change, CWC in different ecosystems exhibits two contrasting responses, “carryover” and “overshoot”. Here, we estimated global CWC using satellite-derived gross primary productivity (GPP) and evapotranspiration (ET) data, and employed partial correlation analysis and explainable boosted regression trees to investigate the spatial patterns and potential factors of the “carryover” and “overshoot” responses of CWC to climate change. Compared with ecosystem model simulations, satellite observations revealed low CWC levels in tropical and arid regions, and accurately captured the strengthening of CWC in polar and boreal regions. Humidification in arid regions promotes the “carryover” response, whereas warming in temperate regions leads to the “overshoot” response. Local drought intensity and biotic factors were identified as decisive in regulating whether CWC exhibits “carryover” or “overshoot” under climate change. Our findings provide a new perspective on the coupling between carbon uptake and water use in terrestrial ecosystems and offer essential theoretical support for improving ecosystem models in the future.