Ecological Risk Modelling, Risk Management, and Environmental Challenges in the 21st Century

The 21st century is marked by unprecedented environmental challenges, including climate change, biodiversity loss, pollution, and ecosystem degradation, all of which pose significant risks to both ecosystems and human well-being. These challenges have been exacerbated by increased industrialization, urbanization, and unsustainable agricultural practices, leading to soil degradation, atmospheric and water pollution, deforestation, and the destabilization of ecological balance and human health (Liang and Song 2022; Ul-Durar et al. 2024). This Special Issue of Risk Analysis addresses two critical risks arising from the environmental challenges discussed earlier: Ecological risks and climate-driven risks. The concept of ecological risk has broadened to include not only ecological impacts but also economic indicators, underscoring the multidisciplinary nature of today's environmental challenges (e.g., Shi et al. 2023; Ul-Durar et al. 2024). Ecological risk modeling and assessment have been continuously explored in numerous previous studies (e.g., Efroymson et al. 2001; Willis et al. 2004; Chen et al. 2025). On the other hand, climate-driven risks affect all aspects of civilization, with multidisciplinary dimensions, and extend from the micro to the macro levels. The erratic and extreme weather, pollution, and numerous other processes are poised to have increasing effects on society, the economy, resource security, population movements, health, ecosystems, and biodiversity in both the global south and global north (e.g., Shortridge and Camp 2019; Li et al. 2025; Anderson et al. 2024). It is therefore crucial to identify, assess, communicate, reduce, mitigate, and manage risks. Modeling risk and understanding its limits are both critical for climate change risk management. There are numerous spillovers and collateral risks associated with climate change to consider: Technological, political, and ethical. Financial instability, disruptive technologies, and political uncertainty complicate the modeling and management of climate risks. The papers published in this issue clearly manifest the innovative work on a range of core climate change-associated risks. They provide new insights through novel risk identification and assessment approaches, leading to profound policy implications for risk analysis and management. The study by Awijen et al. (2025) takes a regional perspective on the risks posed by natural gas leaks in the United States. They examine the localized and regional impacts of natural gas leaks on air quality and safety, with a specific focus on PM2.5 concentrations and incident dynamics across the United States. In so doing, they draw on the Spatial Durbin approach to reveal the significant direct and spillover effects of gas leaks, energy intensity, and environmental regulations on air pollution and safety outcomes. It also underscores the transboundary nature of risks to the air quality, highlighting the necessity of coordinated regional risk management initiatives. Their study also offers actionable risk management recommendations, including strengthening monitoring systems, advancing interregional cooperation, and integrating sustainable energy practices to address the interconnected challenges of air quality management and climate risk mitigation. Assessing the transition risks of environmental regulation is the subject of study by Stylianou et al. (2025). Their analysis identifies transition risk drivers; in particular, it evaluates the implementation of environmental policies in the United States and whether they create risks or foster green innovation and improved financial performance, leading to a low-carbon economy. While their study reports significant transition risks, it also highlights appropriate risk management policies and regulatory frameworks to address them. Like the climate risk, the perception of the climate risk is also essential. In this regard, the study by Ben Ameur et al. (2024) introduces perceived climate risk as an additional factor in asset pricing models. The perceived climate risk is measured based on the climate change sentiment in the Twitter dataset, which includes 16 million unique tweets, and, in so doing, captures perceptions of both physical and transition climate risks. Their study enhances our understanding of the relationship between perceived climate risk and asset prices. The study by Benkraiem et al. (2025) focuses on optimal risk management in the context of environmental and climatic changes. Their paper adopts a regime-switching approach to incorporate the influence of external events, particularly climate change. Various optimal strategies are analyzed under different climate scenarios. Simulations demonstrate the tangible advantages of the continuous-time Markov chain (CTMC) optimal strategy, which outperforms traditional strategies by incorporating adaptive risk. Boubaker et al. (2025) study examines the environmental challenges and risks posed by the CO2 emissions from both long-term and short-term perspectives. Their study highlights that, despite efforts to tackle climate change risks, there appears to be no significant structural change in CO2 emissions that address these crucial risks. To mitigate these risks, they propose a 3.22% reduction per year globally. Accurate measurement of climate risk is vital for the appropriate climate risk management. The study by Ma et al. (2025) introduces an innovative approach to measuring climate risk and uses the Aggregate Climate Change Concern (ACCC) index. The “concern” is defined as the attention paid to the risk of climate change and the associated negative consequences. The aggregate index shows robust predictability of market risk, indicating a strong association between climate risk concerns and the economy. The findings of this study inform the design of adaptive measures and interventions to mitigate ecological risks. Chaudhry et al. (2025) model the risk to environmental, social, and governance (ESG), healthcare, and financial sectors and assess their downside risk, extreme systemic risk, and extreme spillover risk. It turned out that the ESG and healthcare sectors have lower extreme spillover risk (contagion risk) than the financial sector. Their study conducts a comprehensive risk assessment of the ESG, healthcare, and financial sectors, employing an innovative risk-modelling approach to address ecological challenges. Altogether, these studies illustrate that ecological risk modelling, management, and assessment in the 21st century are becoming increasingly complex. There is thus a need for interdisciplinary approaches and the integration of advanced techniques to appropriately measure and assess climate risks, thereby informing social and public policy aimed at mitigating them.