北京师范大学高培超团队最新的研究模拟与分析了1.5℃全球气候承诺对中国土地系统的长期影响。2025年1月9日出版的《中国科学：地球科学》杂志发表了这项成果。

全球变暖已成为人类共同面临的问题。2021年，在《联合国气候变化框架公约》第26次缔约方大会上，与会各国达成了气候承诺，作出更积极的贡献，到2100年将全球平均气温上升控制在1.5℃以内。土地系统变化是土地对气候变化的显著响应。作为缔约方之一，中国近年来提出了碳峰值和碳中和目标等气候目标，以支持将全球变暖限制在1.5°C以内的全球承诺，这将深刻影响中国未来的土地系统变化。

本文以中国为研究区域，生成27种土地系统类型专题的分辨率数据，将全球变化评估模型（GCAM）的各种土地系统类型的输出，整合为四类土地服务需求类别，并将其与改进的CLUMondo模型相结合，模拟了在全球变暖1.5°C情景和不更新减排措施的参考情景下，2100年中国土地系统的变化。

研究结果表明：(1)GCAM与改进的CLUMondo模型相结合的方法，在模拟中国土地系统变化方面具有较高的验证精度，能够有效地预测中国土地系统变化。

(2)在全球变暖1.5°C情景下，中国的山、水、森林、农田、湖泊、草原等生态系统质量有所改善。灌丛、湿地和森林面积预计分别增加185%、79%和33%，其中低密度灌丛、高密度湿地和高密度森林面积增长最为显著。

(3)与参考情景相比，1.5°C气候承诺对未来土地系统的影响更大，湿地和森林面积增长水平分别比参考情景高20%和10%。值得注意的是，耕地、草地和湿地面积的变化在南部和沿海地区更为明显。

(4) 1.5°C情景与参考情景之间最显著的差异是耕地的流失。据估计，到2100年（或更早），现有耕地的35%（截至2020年）将被转换为其他类型，高密度耕地将减少近50%，这将影响粮食安全。农田将主要转化为湿地和森林，以四川盆地、华北平原、东北平原等产粮区为主。

研究结果强调，探讨1.5°C全球变暖气候承诺对中国土地系统的长期影响，对于提出减缓气候变化风险，和促进中国可持续发展的措施具有重要意义。

附：英文原文

Title: Simulation and analysis of the long-term impacts of 1.5°C global climate pledges on China’s land systems

Author: Jiaying LV, Changqing SONG, Yifan GAO, Sijing YE, Peichao GAO

Issue&Volume: 2025/01/09

Abstract: Global warming has become a shared issue for humanity. At the 26th Conference of the Parties to the United Nations Framework Convention on Climate Change in 2021, participating countries reached climate pledges aimed at making more proactive contributions to limit the global average temperature rise within 1.5°C by 2100. Land system changes are significant responses of land to climate change. As one of the contracting parties, China has proposed climate targets such as carbon peaking and carbon neutrality goals in recent years to support the global pledges of limiting global warming to 1.5°C, which will profoundly impact China’s future land system changes. This study focuses on China as the study area, produces data with a thematic resolution of 27 types of land systems, integrates the output of various land types by the Global Change Assessment Model (GCAM) into four categories of land service demand, and combines these with the improved CLUMondo model to simulate China’s land system changes in 2100 under a 1.5°C global warming scenario and a reference scenario without updated emission reduction measures. The conclusions of this study are as follows: (1) The method of integrating the GCAM and improved CLUMondo model demonstrates high validation accuracy in simulating China’s land system changes, effectively predicting the changes. (2) Under the 1.5°C global warming scenario, the quality of ecosystems related to mountains, water, forests, farmland, lakes, and grasslands in China improved. The areas of shrubland, wetland, and forest are projected to increase by 185%, 79%, and 33%, respectively, with low-density shrubland, high-density wetland, and high-density forest showing the most significant increases. (3) Compared with the reference scenario, the 1.5°C climate pledges drive greater changes in future land systems, with wetland and forest area growth levels exceeding those of the reference scenario by 20% and 10%, respectively. Notably, the changes in cropland, grassland, and wetland areas are more pronounced in southern and coastal regions. (4) The most significant difference between the 1.5°C scenario and the reference scenario is the loss of cropland. It is estimated that 35% of the existing cropland (as of 2020) will be converted to other types by 2100 (or earlier), with high-density cropland decreasing by nearly 50%, which will impact food security. Cropland will primarily be converted to wetlands and forests, mainly in grain-producing regions such as the Sichuan Basin, North China Plain, and Northeast Plain. This study explores the long-term impacts of 1.5°C global warming climate pledges on China’s land systems, which is highly important for proposing measures to mitigate climate change risk and promote sustainable development in China.

DOI: 10.1007/s11430-023-1501-9

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-023-1501-9