An alternative explanation to the size and location of the missing sink Robert Andres 1

1. An alternative explanation to the size and location of the missing sink Robert Andres1 Skee Houghton2 1Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6335 USA andresrj@ornl.gov 2Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540 USA

2. Talk Motivations 1. Uncertainty evaluation of FFCO2 time series is an ongoing process. 2. Uncertainty realization effects our collective knowledge of the global carbon cycle.

3. Uncertainty Analysis and FFCO2 Time Series Classic Approach: independent measurements of variable Reality: insufficient number of independent measurements at spatial and temporal scales of interest to the statistical basis of FFCO2 inventories Approach: assess pieces that can be analyzed Several Methods: By mass: spatial scales – global, national, sub-national temporal scales – annual, monthly, … By isotope: stable carbon, radiocarbon available data include combinations of spatial and temporal factors

4. Methodology

5. Methodology

6. Methodology

7. Results Mass weighted average = 9.7% Year weighted average = 9.3%

8. Results

9. Implications:Uncertainty Propagation Example terrestrial biosphere = fossil fuel emissions + land use emissions – oceanic uptake – atmospheric reservoir increase

10. Implications: GCP Data

11. Implications: GCP Data – 2 σ FFCO2

12. Implications: GCP Data + 2 σ FFCO2

13. Conclusions 1. Uncertainty estimates associated with the fossil fuel CO2 term continue to be examined. 2. Uncertainty propagation has implications for understanding the rest of the global carbon cycle components, not only in their magnitude but sometimes as to whether they are a source or sink. 3. Size: may partially be hidden in the error terms of other components Location: may not be on land