How is forest area measured and reported globally?

Forest area is measured using modern remote sensing technologies, satellite imagery, and ground surveys. Organizations like the Food and Agriculture Organization (FAO) of the United Nations track global forest changes through the Global Forest Resources Assessment (FRA), conducted every five years.

Scientists use satellites to capture detailed images of forest cover, distinguishing between dense forests, open woodlands, and degraded land. These images are analyzed with Geographic Information Systems (GIS) to measure how much area is covered by trees.

On the ground, foresters collect data on tree height, species type, and canopy density to validate satellite information. Together, these methods help calculate the total forest area and monitor deforestation, reforestation, and forest degradation trends.

Globally, forest area is expressed as a percentage of total land area. For example, the FAO’s 2020 report estimated that forests cover about 31% of Earth’s land surface.

These measurements are crucial for climate studies, biodiversity management, and policymaking. They help governments understand whether their forests are shrinking or growing and guide conservation efforts to protect one of the planet’s most vital ecosystems.