Climate change is altering the environmental conditions under which geo-hazards develop and occur. Rising temperatures, changing precipitation patterns, glacier retreat, permafrost degradation, sea-level rise, and more frequent or intense extreme weather events are modifying geological, hydrological, and geomorphological systems. These changes may increase the likelihood, magnitude, or spatial extent of landslides, debris flows, rock avalanches, ground subsidence, coastal slope failures, glacial lake outburst floods, and other geo-hazards, posing growing risks to communities, infrastructure, ecosystems, and sustainable development. The effects of climate change are often expressed through interacting or successive hazards rather than through isolated events. Extreme rainfall may initiate widespread slope failures, mobilize sediment into debris flows, block river channels, and lead to barrier-lake formation and subsequent outburst flooding. Glacier retreat and permafrost thaw may destabilize high-mountain slopes, alter sediment availability, and increase the potential for long-runout mass movements and cascading flood hazards. Drought, wildfire, vegetation degradation, and human activities may further modify slope hydrology, surface conditions, and material properties, thereby increasing the susceptibility of landscapes to compound and cascading events.

These processes involve complex interactions among climate forcing, geological conditions, hydrological response, topographic controls, sediment transfer, and human exposure. They are commonly characterized by nonlinear amplification, spatial propagation, cumulative impacts, and delayed responses. Consequently, conventional approaches that assess hazards independently are increasingly insufficient for understanding and managing climate-related geo-hazard risk. Major scientific and technical challenges remain. These include identifying the climatic, hydrological, thermal, and geological thresholds associated with hazard initiation and transformation; quantifying the transfer of material, energy, and risk between successive hazard processes; distinguishing the influence of long-term climate change from natural variability and human disturbance; and predicting cascading hazards across different spatial and temporal scales. Further challenges concern the integration of heterogeneous observations, the development of physically interpretable models, and the translation of scientific findings into practical measures for risk reduction and climate adaptation.

In this context, the establishment of the “Committee on Climate Change and Cascading Geo-Hazards (CCCG)” is timely and strategically important. The Committee will provide an interdisciplinary and international platform for advancing the understanding of climate-sensitive geo-hazards, with particular emphasis on interactions among multiple hazards, cascading processes, and their implications for disaster risk. The Committee will promote research on the effects of extreme rainfall, temperature rise, snow and ice melt, glacier retreat, permafrost degradation, drought, wildfire, sea-level rise, and changing hydrological conditions on the initiation and evolution of geo-hazards. Particular attention will be given to representative cascading processes, including landslide–debris flow, rock avalanche–river blockage–outburst flood, glacier collapse–debris flow, glacial lake outburst flood–sediment disaster, wildfire–rainfall–debris flow, and land subsidence–flooding.

The Committee will encourage the integration of field investigation, long-term monitoring, remote sensing, laboratory testing, physical modeling, numerical simulation, artificial intelligence, and probabilistic risk analysis. It will support the development of shared databases, benchmark case studies, common terminology, technical protocols, and open or comparable modeling frameworks for climate-related cascading geo-hazards. The Committee will also strengthen collaboration among engineering geology, geomorphology, geotechnical engineering, climatology, hydrology, cryosphere science, remote sensing, ecology, risk science, emergency management, and related disciplines. It will promote cooperation among universities, research institutions, government agencies, international organizations, engineering enterprises, and local communities. By linking fundamental research with engineering practice, risk governance, and public policy, the Committee will contribute to more effective prevention, mitigation, preparedness, and response.

The principal objectives of the Committee are to:

1) Advance scientific understanding of the relationships among climate change, environmental evolution, geo-hazard initiation, and cascading hazard processes.

2) Identify the key climatic, hydrological, thermal, geological, and geomorphological thresholds controlling hazard initiation and transformation.

3) Investigate the triggering, propagation, amplification, attenuation, and termination mechanisms of representative geo-hazard chains.

4) Promote integrated observation and monitoring systems combining satellite, airborne, ground-based, and subsurface technologies.

5) Develop physically based, data-driven, and physics-informed approaches for multi-hazard simulation, dynamic risk assessment, impact forecasting, and early warning.

6) Establish shared databases, benchmark cases, standardized terminology, technical protocols, and comparative research frameworks.

7) Support climate-resilient engineering, ecosystem-based mitigation, land-use planning, and adaptive risk-management strategies.

8) Facilitate interdisciplinary, cross-sectoral, and international collaboration, as well as education, training, and capacity building in vulnerable regions.

Through these activities, the Committee on Climate Change and Cascading Geo-Hazards will establish a collaborative platform for understanding and managing geo-hazard risks in a changing climate. It will promote the transition from isolated, single-hazard studies toward integrated analysis of climate–environment–hazard–risk systems and contribute to safer, more resilient, and more sustainable communities.