Contribution of land use to the interannual variability of the land carbon cycle.

Understanding the driving mechanisms of the interannual variability (IAV) of the net land carbon balance (S) is important to predict future climate-carbon cycle feedbacks. Past studies showed that the IAV of S was correlated with tropical climate variation and controlled by semiarid vegetation. But today's land ecosystems are also under extensive human land use and management.

Negative emissions from stopping deforestation and forest degradation, globally.

Forest growth provides negative emissions of carbon that could help keep the earth's surface temperature from exceeding 2°C, but the global potential is uncertain. Here we use land-use information from the FAO and a bookkeeping model to calculate the potential negative emissions that would result from allowing secondary forests to recover. We find the current gross carbon sink in forests recovering from harvests and abandoned agriculture to be -4.