New research reveals that Earth’s plants may be far less effective at soaking up excess CO2 than climate models have long assumed. Credit: Shutterstock High levels of carbon dioxide in the atmosphere are a major driver of climate change. At the same time, increased CO 2 can encourage plants to grow faster, allowing them to absorb more carbon and potentially slow warming. That benefit, however, depends on whether plants have access to enough nitrogen, a nutrient that is essential for growth.