Interactions of the carbon cycle, human activity, and the climate system: a research portfolio

There has never been a greater need for delivering timely and policy-relevant information on the magnitude and evolution of the human-disturbed carbon cycle. In this paper, we present the main thematic areas of an ongoing global research agenda and prioritize future needs based on relevance for the evolution of the carbon–climate–human system. These include firstly, the delivery of routine updates of global and regional carbon budgets, including its attribution of variability and trends to underlying drivers; secondly, the assessment of the magnitude of the carbon–climate feedback; and thirdly, the exploration of pathways to climate stabilization and their uncertainties. Underpinning much of this research is the optimal deployment of a global carbon monitoring system that includes biophysical and socio-economic components.