Climate change is emerging as one of the most pressing global challenges, profoundly influencing the physiological processes of plants. Rising atmospheric carbon dioxide (CO₂) levels, increased temperatures, altered precipitation patterns, and more frequent extreme weather events are disrupting plant growth, development, and productivity. These environmental shifts impact critical physiological functions such as photosynthesis, transpiration, respiration, nutrient uptake, and water-use efficiency. Elevated CO₂ concentrations can stimulate photosynthesis in C₃ plants, a phenomenon known as the CO₂ fertilization effect; however, this benefit is often offset by heat stress and nutrient limitations. Increased temperatures accelerate respiration and may shorten growth periods, leading to reduced biomass accumulation and yield. Water availability, significantly influenced by climate change, affects stomatal behavior, leading to either excessive water loss or limited carbon assimilation. Furthermore, climate-induced oxidative stress elevates the production of reactive oxygen species (ROS), damaging cellular components and impairing plant metabolism unless mitigated by antioxidant defense systems. The physiological responses of plants to climate change are species-specific and can vary even within cultivars, highlighting the need for a detailed understanding at both cellular and whole-plant levels. Insights into these responses are crucial for developing climate-resilient crops through traditional breeding and biotechnological interventions. Adopting sustainable agricultural practices and leveraging stress-tolerant genotypes can help mitigate the adverse impacts of climate change on plant physiology and secure food systems in the future. This chapter explores the multifaceted effects of climate change on plant physiological mechanisms and emphasizes adaptive strategies that enhance plant resilience under changing climatic conditions.