Monitoring Deforestation and Land Use Change

Satellite-based land-cover monitoring reached a decisive milestone with the 2013 publication in Science of "High-Resolution Global Maps of 21st-Century Forest Cover Change," led by Matthew Hansen of the University of Maryland in collaboration with Google and the USGS. The study processed the entire archive of Landsat imagery to produce, for the first time, a consistent global map of forest loss and gain at 30-meter resolution from 2000 onward, a scale of analysis that had previously been computationally infeasible. That dataset now underlies Global Forest Watch, an online monitoring and alert platform launched in 2014 by the World Resources Institute, which combines the Hansen forest-change data with more frequent, lower-resolution alert systems to give researchers, journalists, and policymakers near-real-time visibility into forest loss anywhere on Earth.