Anthropogenic land use conversions in 2023 totaled 28.6 megahectares (Mha), half of which replaced long-lived or secondary natural vegetation, according to the first global land change monitoring system.
Researchers from the University of Maryland led by Amy H Pickens presented the system, known as the OPERA Land Surface Disturbance Alert (DIST-ALERT), in their paper which was published in Nature Communications on October 8, 2025. The system tracks lands that are being changed by human activity, weather events, fires and other causes.
The researchers used DIST-ALERT data to find out how much land around the world changed in 2023 compared to 2020, 2021 and 2022.
The largest share of change was caused by natural variations within the four-year period due to climatic variability, from small and short to substantial drought and green-up events, representing more than two-thirds (1,371 Mha) of all identified change (1,943 Mha).
Fires resulting in land cover conversion totaled 14.9 Mha. Combined, these dynamics equal 0.3 per cent of the global land surface — equivalent to the area of the state of California.
Results showed the human land use footprint expanded at a considerably greater rate than the intensification of current land use types.
Direct human conversion of land cover within 2023 totaled 28.6 Mha. Humans converted 15.7 Mha of long-lived natural vegetation to land use in 2023, comprising about half of total direct human conversion. An additional 3.9 Mha of scrub vegetation on land with prior land use or clearing was converted to human land use. The remaining third of human conversion was from existing land use, such as built-up land replacing agriculture or residential lawns.
The dominant drivers of land use expansion into long-lived natural vegetation were agriculture expansion, logging, shifting cultivation, mining, and built-up expansion. Within existing land use, the drivers were primarily built-up expansion and agriculture intensification.
“The conversion of natural lands to land use is a significant contributor to climate warming,” said Matthew C Hansen, one of the paper’s co-authors. “The result is increasing anomalous weather at the global scale, often seen in our data as large-scale vegetation loss due to fire, drought, floods, and windthrow events”.
Alerting systems that detect land cover change using Earth Observation data have a significant role in providing monitoring information for enforcement, management, and even mitigation. Annual DIST-ALERT summaries of land use expansion and climate-driven land change can serve as a future long-term global environmental data record.