Environmental systems models are essential for understanding the dynamics and mechanisms of various environmental issues (e.g., air pollution, water pollution, floods, droughts, and climate change). Most importantly, they are widely used to predict future outcomes of environmental systems in support of effective decision making and policy development.

However, most of the models are based upon a stationary condition which by default assumes that no significant changes will occur in the future. It has been reported frequently in recent years that such a stationary assumption no longer holds in the context of global climate change and intensive human activities. Many boundary conditions and internal parameters in these models have been changed over time, which leads to considerable uncertainty in future prediction. Therefore, addressing the changing conditions in the process of environmental system modelling and analysis is becoming one of the most challenging issues in the field.

This Special Issue aims to collect recent advances in methodologies, models, tools, and applications for environmental systems modelling and analysis under changing and/or uncertain conditions, such as increasing temperature, changing precipitation patterns, sea-level rise, land cover/use change, urbanisation, and policy changes. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Theory, applications, and tools for nonstationary modelling
• Uncertainty quantification and risk assessment for environmental systems
• Environmental systems modelling and optimisation under changing conditions
• Adaptive management and decision making for emerging environmental issues
• Climate change modelling, analysis, and impact assessment