Interannual-to-Decadal Earth System Variability and Predictability

Interannual-to-decadal variability exerts a fundamental influence on the Earth system by modulating climate, hydrology, ecosystems, biogeochemical cycles, and environmental hazards. Improving our ability to understand and predict variability across these timescales is increasingly important for climate risk assessment, adaptation planning, natural resource management, and ecosystem resilience. Recent advances in observations, Earth system models, data assimilation, and artificial intelligence have substantially enhanced our understanding of Earth system variability. However, interannual-to-decadal predictability remains uniquely challenging because it emerges from the combined effects of internal Earth system variability, slowly evolving Earth system memory, and externally forced climate change. These sources of predictability are further shaped by coupled interactions among the atmosphere, ocean, land, cryosphere, biosphere, and biogeochemical cycles, highlighting the need for an integrated Earth system perspective that bridges traditionally separate disciplines. Advancing our understanding of Earth system predictability across physical, hydrological, ecological, and biogeochemical systems is therefore an emerging frontier in Earth science, providing a scientific foundation for anticipating environmental extremes and compound hazards.

This Research Topic aims to advance understanding of the mechanisms, variability, and predictability of the Earth system on interannual-to-decadal timescales. We welcome contributions investigating the physical, hydrological, ecological, and biogeochemical processes governing variability across the atmosphere, ocean, land, cryosphere, biosphere, and their interactions, as well as studies that quantify sources of predictability using observations, reanalyses, Earth system models, initialized prediction systems, and emerging data-driven approaches.

The Research Topic seeks to foster interdisciplinary studies that connect large-scale Earth system variability with environmental processes, ecosystem dynamics, biogeochemical cycles, and environmental extremes and compound hazards. We also encourage contributions that advance Earth system predictability through improved process understanding, model development, data assimilation, artificial intelligence, uncertainty quantification, predictability theory, and forecast evaluation. By bringing together diverse Earth system disciplines, this Research Topic aims to highlight recent scientific advances and identify future directions for understanding and predicting interannual-to-decadal Earth system variability.

We welcome original research articles, reviews, perspectives, and methodological advances addressing Earth system variability and predictability on interannual-to-decadal timescales. Contributions may focus on individual Earth system components or their interactions and feedbacks. Relevant topics include, but are not limited to:

• Mechanisms of Earth system variability and sources of predictability
• Atmosphere–ocean dynamics and coupled Earth system processes
• Land–atmosphere interactions, hydrological processes, and land surface dynamics
• Marine ecosystems and ocean biogeochemistry
• Terrestrial ecosystems, vegetation dynamics, and biogeochemical cycles
• Cryosphere variability and Earth system feedbacks
• Environmental extremes, natural hazards, and compound events (e.g., droughts, wildfires, heatwaves, floods, and air quality)
• Earth system modeling, initialized prediction systems, and data assimilation
• Artificial intelligence, machine learning, and hybrid Earth system modeling and prediction
• Prediction skill assessment, uncertainty quantification, and predictability theory

Studies spanning regional to global scales are welcome, provided they advance the understanding, predictability, or prediction of Earth system variability on interannual-to-decadal timescales.