A1439
Title: A statistical model of the global carbon budget
Authors: Mikkel Bennedsen - Aarhus University (Denmark) [presenting]
Eric Hillebrand - Aarhus University and CREATES (Denmark)
Siem Jan Koopman - VU Amsterdam (The Netherlands)
Abstract: A dynamic statistical model is proposed for the Global Carbon Budget as represented in the annual data set made available by the Global Carbon Project, covering the sample period 1959-2019. The model connects four main objects of interest: atmospheric carbon dioxide (CO2) concentrations, anthropogenic CO2 emissions, the absorption of CO2 by the terrestrial biosphere (land sink), and by the ocean and marine biosphere (ocean sink). The model captures the global carbon budget equation, which states that emissions not absorbed by either land or ocean sinks must remain in the atmosphere and constitute a flow to the stock of atmospheric concentrations. Emissions depend on global economic activity as measured by World Gross Domestic Product while sink activities depend on the level of atmospheric concentrations and the Southern Oscillation Index. We use the model to determine the time series dynamics of atmospheric concentrations, to assess parameter uncertainty, to compute key variables such as the airborne fraction and sink rate, to forecast the Global Carbon Budget components from forecasts of World Gross Domestic Product and Southern Oscillation, and to conduct scenario analysis based on different possible future paths of global economic activity.
