A new study incorporating satellite data on organic material, or biomass, in tropical forests with experimental data about the effects of temperature and precipitation suggests that forests may lose substantial amounts of carbon by the end of the 21st century. Even with low continued carbon emissions, tropical forests, especially those in the southern Amazon, could lose between 6.8 and 12% of their aboveground carbon. With higher emissions, they could lose 13.3 to 20.1% of their carbon stores. The results highlight the need to reduce global temperatures rapidly to maintain the healthy forests best able to sequester carbon from the atmosphere. The team reported their findings Feb. 6 in the journal Nature Climate Change.