As an Amazonian country, Peru knew it was doing the world an environmental service by storing carbon in its rainforest. But the country didn’t know exactly how much carbon it was keeping out of the atmosphere nor precisely where it was. That hindered its ability to protect its reserves as well as negotiate a fair price for doing so on the global carbon market. Now, a new map provides a hectare-by-hectare look at Peru’s carbon reserves. Made by combining data from LiDAR flights, a network of monitored land plots, and satellite imagery, the map reveals that Peru stores just under 7 billion metric tons of carbon, mostly in the Amazon rainforest that dominates the eastern part of the country, researchers report online today in the Proceedings of the National Academy of Sciences. The map is so detailed that it can reveal deforestation that would otherwise be hidden deep in rural areas. The image above, for example, shows how carbon stocks are diminished by the building of a road (blue) through the normally high-carbon Amazon (red). These kinds of close-ups allowed the researchers to calculate that at least 800 million metric tons of Peru’s aboveground carbon stocks are at imminent risk of destruction from activities such as logging and oil extraction. But there’s hope: The map also shows that federally protected environmental reserves are great at storing carbon, which could give the Peruvian government the leverage it needs to establish more of them. Meanwhile, the team hopes to expand its mapping method to more developing tropical countries. Next up? Ecuador.