A greening Earth has reversed the trend of decreasing carbonate weathering under a warming climate
Sibo Zeng, Zaihua Liu, Yongjun Jiang, Nico Goldscheider, Yan Yang, Min Zhao, Hailong Sun, Haibo He, Mingyu Shao, Liangxing Shi
Abstract
The response of mineral weathering and its related Weathering Sink for atmospheric CO2 (WSatm-CO2) to global vegetation greening are not well understood. After applying different biogeochemical models and a field experiment to investigate the influence of vegetation greening and warming on the variations of carbonate weathering and WSatm-CO2 on regional and global scales, here we show a significant positive relationship between global carbonate weathering intensity ([HCO3−] as a proxy) and vegetation greenness. During 1982–2018, under a warming climate, [HCO3−] and WSatm-CO2 increase by 5.8% and 6.1%, respectively, due to vegetation greening, in the carbonate areas of Southwest China. Meanwhile, the [HCO3−] in global carbonate areas increases by +2.4% during the same period. By contrast, the [HCO3−] in global carbonate areas decreases by −1.3% without a vegetation function due to the warming. Moreover, we estimated that the carbonate weathering enhancements due to vegetation restoration at the global scale could reach 43.8%. Our results demonstrate that future vegetation restoration is important for the carbon capture by mineral weathering. A positive relationship between carbonate weathering and vegetation greenness has been found, indicating a greening Earth has reversed the trend of decreasing weathering under the warming climate. Therefore, future vegetation restoration is important for carbon capture by mineral weathering.