4C has three overall scientific objectives to tackle persistent knowledge gaps in climate science, all supporting a fourth objective of knowledge transfer. 4C will achieve these scientific objectives using new observations and observational techniques, together with enhanced process understanding and new improvements in Earth system modelling for better understanding past and anticipating future changes.
The objectives of 4C are the following:
Objective 1: Improve our understanding of processes controlling the global carbon cycle
- 4C aims to make a major improvement in our understanding of the global carbon cycle over the historical period, by producing a comprehensive set of novel constraints using innovative methods and new observations, and applying these new constraints to critically assess and improve current carbon cycle models. 4C will focus particularly on different processes, such as the nitrogen and phosphorous control on the strength of the carbon sink on land, the land water control on land carbon sink etc.
Objective 2: Develop a near-term prediction of the climate and carbon cycle
- 4C will develop new tools and methods to predict for the first time the evolution of global carbon cycle variability over the coming decade, including atmospheric CO2, land and ocean carbon sinks, and predict the climate response in order to track the overall progress towards the goal of the Paris Agreement.
Objective 3: Reduce uncertainties in climate projections over the 21st century
- 4C will improve our understanding on climate-carbon feedbacks and provide a robust quantification of their evolution over the 21st century, using new constraints from historical observations to inform the analysis of ESM projections.
Objective 4: Knowledge transfer
- 4C will ensure the usability of the knowledge generated by scientific research and engage in bilateral interactions among scientists and policy makers. The scientific findings will foster a broader understanding of climate-carbon interactions and accurate interpretation of the findings, communicating the results to a wider audience.