The greenhouse gas concentration spreadsheet has been cleaned up.
The previous version had zeros inserted for some gases where there was no observation. We leave these blank here as they are missing data, but for forcing purposes we assume zero unless they are after a year where a non-zero value is measured in which case we assume persistence. For i-C6F14 there was also missing data for non-decadal years from 1990 that were filled in with zero. These should not have been filled in with zero, and interpolation would be more appropriate (as is done now). This update changes the ERF time series ever so slightly - in the 4th or 5th decimal place - for non-decadal years since 1990. It does not affect the overall assessment, or change any values in Annex III which are given on decadal time intervals. Knock-on impacts will be negligible - it is unlikely to affect any constraining for projections, or be visible in the plot to fig. 2.10.
The greenhouse gas concentration spreadsheet has been cleaned up.
The previous version had zeros inserted for some gases where there was no observation. We leave these blank here as they are missing data, but for forcing purposes we assume zero unless they are after a year where a non-zero value is measured in which case we assume persistence. For i-C6F14 there was also missing data for non-decadal years from 1990 that were filled in with zero. These should not have been filled in with zero, and interpolation would be more appropriate (as is done now). This update changes the ERF time series ever so slightly - in the 4th or 5th decimal place - for non-decadal years since 1990. It does not affect the overall assessment, or change any values in Annex III which are given on decadal time intervals. Knock-on impacts will be negligible - it is unlikely to affect any constraining for projections, or be visible in the plot to fig. 2.10.