A Carbon–Water nexus framework for agricultural systems: Insights from Turkish agriculture

Agricultural sustainability is constrained by water scarcity and climate change, necessitating integrated approaches that move beyond single-indicator assessments. This review synthesizes carbon footprint (CF) and water footprint (WF) evidence within a carbon-water nexus perspective using Turkish agricultural as a case study. A literature-based dataset was constructed by combining reported CF values with observed and benchmark WF data from national and global sources. Three complementary approaches were applied: (i) carbon-water efficiency frontier analysis based on a Pareto framework, (ii) irrigation carbon penalty assessment using blue water use-emission relationships, and (iii) variability analysis of CF consistency across studies. The integrated comparison reveals a non-linear pattern between CF and WF, with agricultural systems clustering into distinct environmental regimes. Efficiency frontier analysis identifies non-dominated systems characterized by relatively balanced resource use, while irrigation-intensive systems consistently emerge as environmental hotspots. The irrigation carbon penalty perspective indicates that increasing blue water use is generally associated with higher carbon emissions due to energy requirements; however, the magnitude of this effect varies across crops, indicating strong system dependency. In addition, substantial variability in reported CF values highlights the influence of methodological choices and system boundaries on footprint estimates. These findings demonstrate that sustainability in agricultural systems cannot be adequately assessed through isolated metrics and require integrated, nexus-based approaches. The synthesis framework provides a basis for identifying priority mitigation areas and supports crop-specific and context-sensitive management strategies. While developed for Türkiye, the proposed approach is transferable to other regions facing similar challenges related to water scarcity, agricultural intensification, and decarbonization.