Tropical woody plants store ∼230 petagrams of carbon in their above-ground living biomass. These stocks are currently growing in primary forests at rates that have decreased in recent decades. Droughts are an important mechanism in reducing forest carbon uptake and stocks by elevating tree mortality, increasing autotrophic respiration, and promoting wildfires. With continued climate change, the intensity and frequency of droughts will likely increase, with land-use change intensifying their effects.