A study published in Nature Communications reveals that the positive indirect effects of elevated atmospheric CO₂ (eCO₂) on vegetation carbon uptake have declined in recent decades, shifting to negative in the early 21st century, particularly in high latitudes. This shift is attributed to a combination of reduced direct CO₂ physiological effects and widespread land drying, which has weakened the overall carbon uptake benefits from climate warming and CO₂ fertilization. The research, using satellite observations and Earth system models, shows that the indirect CO₂ effect has significantly decreased globally from 1982–1996 to 2000–2014, with a further projected decline under the SSP5-8.5 scenario by 2100. The negative indirect effect is expected to dominate future vegetation carbon uptake, especially in the Northern Hemisphere, leading to a potential negative carbon-climate feedback. The study highlights the complex interactions between climate change and vegetation responses, emphasizing the role of water limitation and the saturation of CO₂ fertilization effects. These findings underscore the need for updated climate mitigation strategies to address the reduced capacity of terrestrial ecosystems to sequester atmospheric CO₂.A study published in Nature Communications reveals that the positive indirect effects of elevated atmospheric CO₂ (eCO₂) on vegetation carbon uptake have declined in recent decades, shifting to negative in the early 21st century, particularly in high latitudes. This shift is attributed to a combination of reduced direct CO₂ physiological effects and widespread land drying, which has weakened the overall carbon uptake benefits from climate warming and CO₂ fertilization. The research, using satellite observations and Earth system models, shows that the indirect CO₂ effect has significantly decreased globally from 1982–1996 to 2000–2014, with a further projected decline under the SSP5-8.5 scenario by 2100. The negative indirect effect is expected to dominate future vegetation carbon uptake, especially in the Northern Hemisphere, leading to a potential negative carbon-climate feedback. The study highlights the complex interactions between climate change and vegetation responses, emphasizing the role of water limitation and the saturation of CO₂ fertilization effects. These findings underscore the need for updated climate mitigation strategies to address the reduced capacity of terrestrial ecosystems to sequester atmospheric CO₂.