Longman Jack, Mills Benjamin J W, Merdith Andrew S
Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, UK.
Marine Isotope Geochemistry, Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, Germany.
Nat Commun. 2025 May 23;16(1):4813. doi: 10.1038/s41467-025-59480-0.
The emplacement of large igneous provinces (LIPs) is known to be a driver of climate change in Earth's past. However, the balance of climate warming through CO emission and cooling through weathering is poorly understood. To better understand the role of LIP emplacement on long-term climate change, here we utilize the SCION coupled climate-biogeochemical model which considers the impact of LIPs through degassing of CO and enhancement of local continental weathering rates. This approach results in better correspondence between the modelled output and proxy reconstructions of the period (especially for seawater Sr isotope composition) when compared to previous modelling studies. Of the seven LIPs during the breakup phase of Pangaea (approximately 300-150 Ma), only the Central Atlantic Magmatic Province (CAMP) drives noticeable long-term cooling in the model, a minor effect (between 1-2 °C) despite emplacement of a very large surface area in the humid tropics. Similarly, only the CAMP imparts a significant change in the long-term Sr isotope record whereas the other LIPs of this period do not. Due to limited areal extents, and emplacement outside tropical weathering zones, we conclude most LIPs have no significant global cooling effect on multimillion year timescales.
已知大火成岩省（LIPs）的形成是地球过去气候变化的一个驱动因素。然而，通过二氧化碳排放导致的气候变暖与通过风化作用导致的气候变冷之间的平衡却鲜为人知。为了更好地理解LIPs的形成对长期气候变化的作用，我们在此使用了SCION耦合气候 - 生物地球化学模型，该模型通过二氧化碳脱气和当地大陆风化速率的增强来考虑LIPs的影响。与之前的建模研究相比，这种方法使得模拟输出与该时期的代理重建结果（特别是海水锶同位素组成）之间具有更好的对应关系。在泛大陆解体阶段（约3亿至1.5亿年前）的七个LIPs中，只有中央大西洋岩浆省（CAMP）在模型中导致了明显的长期变冷，尽管在潮湿的热带地区有非常大的面积形成，但这种影响较小（在1至2摄氏度之间）。同样，只有CAMP在长期锶同位素记录中产生了显著变化，而该时期的其他LIPs则没有。由于面积范围有限，且形成于热带风化带之外，我们得出结论，大多数LIPs在数百万年的时间尺度上对全球没有显著的降温作用。
