Abiotic stressors, such as drought, salinity, extreme temperatures, and nutrient imbalances, negatively impact crop development and productivity, posing serious risks to global food security. Climate change exacerbates these stressors, leading to soil degradation, water scarcity, and the loss of agricultural land. Although transgenic and conventional breeding systems have improved stress tolerance, their effectiveness is constrained by extended developmental stages and poor precision. CRISPR/Cas9 genome-editing technology provides a unique and efficient platform for the accurate modification of stress-responsive genes, enabling rapid growth of resilient crop variants. This study examines advances in CRISPR/Cas9 applications to improve abiotic stress tolerance in crops such as rice, maize, wheat, and soybean. Key genes associated with osmotic regulation, ion transport, antioxidant defense, and stress-related signaling are addressed together with multiplex editing and promoter engineering techniques.

In the context of environmental science, CRISPR/Cas9-driven crop enhancement facilitates sustainable ecosystems by reducing dependency on chemical fertilizers, over-irrigation, and soil additives, thereby lowering greenhouse gas emissions and mitigating ecological consequences. The development of stress-tolerant cultivars also promotes sustainable land management and climate-smart agricultural technologies. Nevertheless, biosafety concerns, adverse consequences, and regulatory challenges necessitate a thorough environmental risk assessment before large-scale implementation. In conclusion, CRISPR/Cas9 is a breakthrough biotechnological innovation that integrates molecular genetics and ecological sustainability, paving the way for more resilient agricultural systems in an evolving climate.