Land-use change is the principal direct driver of terrestrial biodiversity loss — and effectively halting it across the world’s forests, peatlands, grasslands and coastal wetlands represents a critical step toward reversing rapid declines in nature.
Agricultural expansion is the leading driver of deforestation and degradation
Agricultural expansion poses the most significant threat to these ecosystems, with urbanization, mining and afforestation exerting smaller but increasingly acute pressures. Clearing forests to make way for croplands and pasturelands drove nearly 95% of deforestation globally between 2016 and 2025, while aquaculture, rice cultivation and palm oil production collectively spurred roughly 43% of mangrove losses between 2000 and 2020. Similarly, agricultural activities are primarily responsible for degradation across peatlands and grasslands, with recent years seeing a sharp rise across the tropics.
How deforestation, other forms of ecosystem conversion, and degradation threaten biodiversity
These land-use changes ultimately shrink, fragment or otherwise degrade thousands of species’ habitats, which reduces their total abundance and richness across terrestrial ecosystems and heightens the risk of local and global extinctions. Subsequent changes in the composition of species — and how they interact with each other — can also alter ecosystem functions and undermine the delivery of vital ecosystem services to humanity. These losses in species, ecosystem functions and ecosystem services are not always linear and can accelerate quite rapidly. They can also be quite difficult to recover — and in some instances may be irreversible.
How land-use change exacerbates climate change by disrupting carbon sequestration and storage
By disrupting carbon cycling across forests, peatlands, grasslands and coastal wetlands, land-use change is also exacerbating climate change. Together, these ecosystems hold roughly 1,800 gigatons of carbon (GtC) — more than triple the total amount of carbon emitted from fossil fuels since 1850.
One estimate indicates almost a quarter of these carbon stocks (~440 GtC) are highly vulnerable to human disturbances and would be released following conversion to croplands, urban development or other land-uses. Some of these carbon losses can occur quite rapidly, such as when large-scale commodity producers clear-cut forests for agricultural production.
Once lost, much of this carbon would be difficult for ecosystems to recover in time to help the world reach net zero by around mid-century. For example, fully rebuilding depleted carbon stocks could take 6-10 decades for forests, well over a century for mangroves and centuries to millennia for peatlands. Therefore, effectively halting deforestation, other forms of ecosystem conversion and ecosystem degradation, can deliver the lion’s share of mitigation needed from the land sector through 2050.
The world has largely fallen short in halting deforestation and degradation
Despite the significant role that protecting terrestrial ecosystems — particularly those that are intact and relatively undisturbed by human activities — can play in combatting the climate and biodiversity crises, global efforts to effectively halt deforestation, other forms of ecosystem conversion and degradation remain vastly inadequate. Across all indicators with sufficient data and near-term targets, recent rates of change are either well off track or heading in the wrong direction entirely. And even where data is too limited to assess global progress, available evidence suggests that current actions are falling short and dramatic changes are urgently needed to get on track.
Join us on October 27 for the launch of new data and insights on the state of the world's forest and land.
