Story: Because of NASA, we can calculate roughly how many trees we have on Earth. Trees, both leafy and otherwise, reflect sunshine in very particular patterns, making it possible for satellites to map and computers to count strips of land where trees are. Biologists can then sample those places — forests, suburbs, city parks, even city streets — assume a tree density, multiply by acre or hectare, and calculate that. In 2005, there were 400,246,300,201 (more or less) trees on our globe.

Story: Because of NASA, we can calculate roughly how many trees we have on Earth. Trees, both leafy and otherwise, reflect sunshine in very particular patterns, making it possible for satellites to map and computers to count strips of land where trees are. Biologists can then sample those places — forests, suburbs, city parks, even city streets — assume a tree density, multiply by acre or hectare, and calculate that. In 2005, there were 400,246,300,201 (more or less) trees on our globe.