When the lights come on: The hidden carbon cost of a brightening world

Abstract Nighttime satellite imagery has long served as a proxy for human development, equating light with progress and darkness with poverty. Here, we argue that this framing obscures a critical climate reality: the world's darkest regions, dominated by smallholder agriculture across central Africa, Southeast Asia, and the remote tropics, are simultaneously low‐emission zones and active carbon sinks, a dual function overlooked by Nationally Determined Contributions (NDCs), national Paris Agreement pledges for greenhouse gas reductions. Drawing on recent evidence that artificial light at night suppresses ecosystem carbon storage by accelerating nocturnal respiration, we identify a structural blind spot in global climate governance: as these regions urbanize, they will undergo a carbon double shock, losing sink capacity while rapidly becoming new emission sources. We propose that nighttime light data be integrated into NDC frameworks as an early warning tool to anticipate and govern this transition before it materializes in national emissions inventories.