🛰️ Satellites
In 2013, Global Forest Watch launched a platform that fundamentally changed the politics of tropical deforestation. For the first time, anyone with an internet connection could see, in near-real-time, where forest was being cleared — down to individual clearings of a few hectares, anywhere in the world. Governments could no longer deny deforestation was occurring in protected areas. Companies could be held accountable for supply chain links to deforested land. Communities could document illegal clearing in their territories and report it to authorities with satellite evidence. The era of satellite accountability for forest loss had begun.
GLAD alert latency (Landsat-based)
spatial resolution of GLAD alerts
Global Forest Watch registered users
Sentinel-based fire alerts
The GLAD (Global Land Analysis and Discovery) alert system, developed by the University of Maryland in partnership with Global Forest Watch, analyses Landsat satellite imagery to detect significant changes in forest cover. Every 8-16 days, Landsat satellites image the entire Earth's surface. GLAD algorithms compare each new image with historical baselines for that location, flagging areas where forest cover has declined significantly. The alert is then transmitted to subscribers — government agencies, NGOs, journalists, and community monitors — who can investigate on the ground or escalate to authorities.
While GLAD alerts detect forest clearing, a complementary system monitors fire — one of the primary tools used to clear tropical forest. NASA's FIRMS (Fire Information for Resource Management System) processes data from multiple satellites including Terra, Aqua, and the Suomi NPP satellite to detect active fires globally, with a latency of approximately 3 hours. In the Amazon, this data feeds into Brazil's INPE fire monitoring system and into Global Forest Watch Fire, which provides near-real-time fire alerts overlaid on forest cover maps — allowing rapid identification of fires that may indicate illegal forest clearing.
| System | Satellite | Resolution | Latency | Coverage |
|---|---|---|---|---|
| GLAD Alerts | Landsat 8/9 | 30m | 8-16 days | Global tropics |
| RADD Alerts | Sentinel-1 SAR | 10m | 12 days | Tropics (all weather) |
| FIRMS Fire | VIIRS/MODIS | 375m/1km | 3 hours | Global |
| Planet Labs | PlanetScope | 3m | Daily | Global (commercial) |
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Dr. Nair has spent 14 years developing and deploying technology solutions for tropical forest conservation across Southeast Asia, the Amazon, and the Congo Basin. Her research bridges satellite remote sensing, AI, and community-based monitoring to make conservation technology accessible at scale.