Elevated CO2 helps soybean plants cope better with drought stress by making them more efficient in using water. The study looked at how soybeans respond to higher CO2 levels and drought conditions. Drought reduced the soybean yield and affected photosynthesis, while elevated CO2 increased the plant's ability to photosynthesize and produce more yield. The combination of elevated CO2 and drought improved the plant's water-use efficiency and reduced the negative effects of drought on photosynthesis. This research suggests that elevated CO2 levels can help soybeans withstand drought better by improving their ability to use water efficiently.