Behavioral heterogeneity and system resilience in the face of climate change: an agent-based modeling approach in northern Italy

Climate change poses a profound risk to farming activities, threatening agricultural productivity and livelihoods through increasing temperatures, erratic rainfall patterns, and frequent extreme weather events. These challenges raise critical questions about the resilience of farming systems, particularly under diverse socio-economic and environmental pressures. Resilience must be understood in terms of both system-level dynamics and individual actors, whose decision-making processes exhibit significant heterogeneity. Farmers’ unique preferences, perceptions, and strategies necessitate well-defined policies that consider individual behaviors to enhance resilience. Agent-based modeling (ABM) offers a robust framework to address these challenges by explicitly representing the diversity of actors and their behaviors while simulating the impacts of climate threats and policy interventions on farming systems.

This study adopts a novel agent-based framework, ABNexus, designed to analyze the resilience of the Adda River farming system in northern Italy. ABNexus integrates an ABM with a distributed-parameter water balance crop yield model, IdrAgra, to provide high spatial resolution and behavioral flexibility. The model uses survey data collected from 460 local farms to calibrate farmer profiles, capturing the diversity of decision-making processes based on farm characteristics, climate change awareness, perceived impacts, and adaptation strategies. Farmers were categorized into three distinct clusters—risk-averse, risk-neutral, and risk-taker— reflecting behavioral traits that influence their decision-making criteria within the ABM framework. We also implemented different behavioral modes, ranging from profit maximization under perfect foresight to differentiated risk aversion under uncertainty, and assessed their alignment with observed decisions over the past 20 years.

Building upon this validated framework, we assessed the resilience of the Adda River basin farming system under various climate change scenarios, such as an increased frequency of severe drought years. We further explored the impact of targeted policy interventions, such as subsidies for the adoption of water-efficient irrigation technologies.

Our results highlight the importance of incorporating behavioral heterogeneity in agricultural modeling. Historical analysis revealed that behavioral assumptions significantly influence the alignment of simulated decisions with real-world observations, underscoring the need for detailed behavioral representations. Preliminary findings from scenario testing indicate that targeted subsidies for irrigation technology adoption can enhance system resilience. However, the magnitude and distribution of these benefits vary across different behavioral assumptions, reflecting farmers’ diverse responses to policy interventions. This research provides valuable insights into the complex interplay between human behavior, climate change, and agricultural system resilience. The ABNexus framework offers a valuable tool for exploring the potential impacts of various climate change scenarios and evaluating the effectiveness of policy interventions.