Global land use and land cover (LULC) change plays a critical role in environmental change, biodiversity conservation, climate regulation, and ecosystem services. Over the past few decades, multiple global LULC datasets—such as MCD12Q1, ESA CCI-LC, GLC-FCS30D, HYDE 3.3, HILDA+ , and LUH2—have been developed using remote sensing or historical reconstruction. In this study, we comprehensively analyse the similarities and discrepancies among six global LULC datasets, revealing land-cover changes and transitions from 2001 to 2019. The most significant global LULC changes during this period include forest loss, cropland gain, and settlement expansion. The mutual conversion between forest and cropland was particularly prominent, accounting for around 20 % of all land-use transitions. However, notable discrepancies exist among the datasets in capturing global LULC changes. For example, estimates of net forest area change vary from an increase of 1.10×105km2 to a decrease of 1.55×106km2, while cropland area changes vary from a rise of 1.59×106km2 to a decline of 4.11×104km2. Settlement areas saw the most significant increase in the GLC-FCS30D dataset. These differences were most pronounced in Africa and South America for forest loss and cropland gain, and in Asia for settlement expansion. Comparisons with FAOSTAT show that GLC-FCS30D and HYDE 3.3 align closely with cropland changes, while HILDA+ closely matches forest change data. These findings highlight the importance of harmonizing LULC datasets to improve the accuracy of global land change assessments and support better environmental management strategies.

中文翻译：

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2001 年至 2019 年全球土地变化情景的不同

全球土地利用和土地覆盖 （LULC） 变化在环境变化、生物多样性保护、气候调节和生态系统服务中发挥着关键作用。在过去的几十年里，已经使用遥感或历史重建开发了多个全球 LULC 数据集，例如 MCD12Q1、ESA CCI-LC、GLC-FCS30D、HYDE 3.3、HILDA+ 和 LUH2。在本研究中，我们全面分析了六个全球 LULC 数据集之间的相似性和差异性，揭示了 2001 年至 2019 年土地覆盖的变化和转变。在此期间，全球 LULC 最显著的变化包括森林损失、农田增加和定居点扩张。森林和农田之间的相互转换尤为突出，约占所有土地利用转变的 20%。但是，数据集在捕获全局 LULC 变化方面存在显着差异。例如，估计的森林净面积变化从增加 1.10×105 平方公里到减少 1.55×106 平方公里不等，而农田面积变化从增加 1.59×106 平方公里到减少 4.11×104 平方公里不等。在 GLC-FCS30D 数据集中，定居区的增长最为显著。这些差异在非洲和南美洲的森林损失和耕地增加方面最为明显，在亚洲的定居点扩张方面最为明显。与 FAOSTAT 的比较表明，GLC-FCS30D 和 HYDE 3.3 与耕地变化密切相关，而 HILDA+ 与森林变化数据密切相关。这些发现强调了协调 LULC 数据集以提高全球土地变化评估的准确性并支持更好的环境管理策略的重要性。