Urban irrigation can help counteract climate-carbon feedback by reducing heat and carbon emissions. This study investigates the impact of urban irrigation on ambient temperatures and CO₂ exchange in major U.S. cities. Modeling results show that in humid regions, irrigation reduces carbon emissions through evaporative cooling, while in arid regions, it increases soil moisture and thus carbon emissions. The environmental co-benefit of irrigation in heat and carbon mitigation is positively correlated with urban greening. Urban areas, covering 3% of global land, account for 56% of the population and produce over 70% of global CO₂ emissions. Urbanization is a major driver of climate change, leading to heat stress, pollution, and ecosystem degradation. Anthropogenic heat emissions, including CO₂, contribute to climate change, creating a positive feedback loop. Urban greening, such as lawns, trees, and irrigation, is widely used to mitigate heat and carbon emissions. However, quantifying the impact of urban greening on climate remains challenging due to uncertainties in biogenic CO₂ exchange and limited global observations. Recent studies highlight gaps in implementing nature-based solutions, including uncertainties in effectiveness and lack of public awareness. Understanding the interactions between urban vegetation and its surroundings is crucial for addressing these challenges. Urban irrigation affects CO₂ exchange through both cooling and moisturizing effects, with contrasting findings on its environmental impact. While irrigation can reduce air temperature, it may also increase soil respiration, leading to carbon release. The study uses a modeling framework based on the WRF model and ASLUM to analyze the complex interactions between heat and carbon dynamics in urban environments. Results show that urban irrigation cools cities by 0.26°C on average, with significant cooling during heatwaves. However, irrigation can also increase CO₂ emissions, particularly in arid regions. The study finds that the impact of irrigation on CO₂ exchange varies by region, with some cities experiencing increased carbon emissions and others reduced emissions. The study highlights the need for precise irrigation management to maximize environmental co-benefits and minimize trade-offs. Urban irrigation can have both positive and negative effects on carbon exchange, depending on local conditions. The study recommends optimizing irrigation to enhance carbon sequestration while reducing respiration. The findings suggest that urban irrigation can contribute to carbon reduction, but careful management is needed to avoid unintended carbon release. The study also emphasizes the importance of integrating water, energy, and environmental indicators in urban planning to achieve sustainable climate mitigation. The results highlight the need for further research to optimize irrigation strategies and improve urban climate models to address climate-carbon feedback. The study's findings have implications for sustainable urban development and climate policy, emphasizing the role of urban green spaces in carbon budgeting. The study also identifies limitations in current data and modeling approaches, calling for more comprehensive datasets and advanced modeling techniques to improve the accuracy of urban climate predictions. The study underscores the importance of balancing urban cooling and carbon sequestration to achieve sustainable climate solutions.Urban irrigation can help counteract climate-carbon feedback by reducing heat and carbon emissions. This study investigates the impact of urban irrigation on ambient temperatures and CO₂ exchange in major U.S. cities. Modeling results show that in humid regions, irrigation reduces carbon emissions through evaporative cooling, while in arid regions, it increases soil moisture and thus carbon emissions. The environmental co-benefit of irrigation in heat and carbon mitigation is positively correlated with urban greening. Urban areas, covering 3% of global land, account for 56% of the population and produce over 70% of global CO₂ emissions. Urbanization is a major driver of climate change, leading to heat stress, pollution, and ecosystem degradation. Anthropogenic heat emissions, including CO₂, contribute to climate change, creating a positive feedback loop. Urban greening, such as lawns, trees, and irrigation, is widely used to mitigate heat and carbon emissions. However, quantifying the impact of urban greening on climate remains challenging due to uncertainties in biogenic CO₂ exchange and limited global observations. Recent studies highlight gaps in implementing nature-based solutions, including uncertainties in effectiveness and lack of public awareness. Understanding the interactions between urban vegetation and its surroundings is crucial for addressing these challenges. Urban irrigation affects CO₂ exchange through both cooling and moisturizing effects, with contrasting findings on its environmental impact. While irrigation can reduce air temperature, it may also increase soil respiration, leading to carbon release. The study uses a modeling framework based on the WRF model and ASLUM to analyze the complex interactions between heat and carbon dynamics in urban environments. Results show that urban irrigation cools cities by 0.26°C on average, with significant cooling during heatwaves. However, irrigation can also increase CO₂ emissions, particularly in arid regions. The study finds that the impact of irrigation on CO₂ exchange varies by region, with some cities experiencing increased carbon emissions and others reduced emissions. The study highlights the need for precise irrigation management to maximize environmental co-benefits and minimize trade-offs. Urban irrigation can have both positive and negative effects on carbon exchange, depending on local conditions. The study recommends optimizing irrigation to enhance carbon sequestration while reducing respiration. The findings suggest that urban irrigation can contribute to carbon reduction, but careful management is needed to avoid unintended carbon release. The study also emphasizes the importance of integrating water, energy, and environmental indicators in urban planning to achieve sustainable climate mitigation. The results highlight the need for further research to optimize irrigation strategies and improve urban climate models to address climate-carbon feedback. The study's findings have implications for sustainable urban development and climate policy, emphasizing the role of urban green spaces in carbon budgeting. The study also identifies limitations in current data and modeling approaches, calling for more comprehensive datasets and advanced modeling techniques to improve the accuracy of urban climate predictions. The study underscores the importance of balancing urban cooling and carbon sequestration to achieve sustainable climate solutions.