Forest degradation and biodiversity losses caused by land conversion and over-use have strongly increased since the mid-20th century. Today, only 22% of the global forest area remains as intact forest with little human activity or habitat fragmentation. Despite their exceptional value for global biodiversity conservation, ecosystem services and human well-being, only 12% of the intact forests are protected, and many intact forests risk degradation from climate change and increasing human pressures, e.g. conversion to agriculture, extractive harvesting, and fragmentation. However, forest transitions - shift from net deforestation to net reforestation - have occurred widely and rapidly in recent decades. These net increases in forest area are due to active afforestation, reforestation, and spontaneous reforestation following land abandonment. In addition to increases in forest area, reversals from forest degradation to net gains in tree cover and forest quality are also reported from degraded forests. Recent studies highlight that global forest restoration provides us with an important opportunity for climate change mitigation. However, the restoration of biodiversity and ecosystem processes often fails, e.g. when monocultures are planted, if the landscape is fragmented, or due to social, political, and economic pressures. The need to develop strategies for shaping forest transitions has been increasingly highlighted, with active restoration becoming a global priority with billions of dollars invested. The overall objective of FAIR is to link the trajectories of global forest transitions dynamic (i.e. de- to reforestation shifts and analogous shifts in intactness) to societal and climate change. FAIR relies strongly on remote sensing remote sensing satellite data, which has tremendous potential to map, quantify, and monitor forest change at global scale. We found that: 1) remotely sensed tree-cover heterogeneity can easily distinguish tree plantations from primary and secondary forests. 2) that human factors are the second-most important driver of forest structure after climate - both globally and regionally. It even had dominant influence on forest structure in protected areas and intact forest landscapes. 3) greater influence of climate, human activities, and fire on the structure of naturally regrown forests compared to planted forests globally, particularly in areas with low human development, indicating that naturally regrown forests are at particularly high risk from anthropogenic pressures and climate stress.
