Important Take-Home Messages
- CarbonTracker will evolve with time as scientists' understanding of the carbon cycle progresses. However, the largest improvements are expected to come from more long-term measurements of atmospheric CO2 distributed over the globe.
- Given the short-term variability of CO2 at any point in the atmosphere, it is crucial to make long-term and very high-precision measurements. This has been the NOAA ESRL GML mission for the past 40 years.
- The CarbonTracker results give an estimate of the sources and sinks of CO2 with an associated estimate of the error. The smaller the error, the more trustworthy a particular source or sink estimate is. Results are provided in a normal statistical form: a mean and a standard deviation (σ). This means that there is a 95% chance that the true value is within 2 x σ of the mean value. The error associated with a particular source estimate depends on 1) how well the source may be known a priori; 2) how well the measurements can constrain the source; and 3) how good the measurements are. For example, a source upwind of a measurement tower will be better constrained than a source with no downwind measurements.
- CarbonTracker is an "objective" tool. It reconciles our understanding of CO2 sources and sinks with the actual atmospheric CO2 measurements. It is a unique tool to "check the books" of the atmospheric CO2 "account".
