CLIMATE CHANGE: Variable Carbon Sinks.

Over half of the anthropogenic carbon dioxide emitted into the atmosphere is partially absorbed by carbon sinks. As Fung explains in this Perspective, determining the location and magnitude of these sinks remains a major challenge. Bousquet et al. find that regional and global terrestrial carbon sinks are much more variable than their oceanic counterparts and that the tropical land masses may play a major role. Given that the land sink is so variable, it is uncertain how it will repond to climate change.