Box 3b: Further explanation of LULUCF accounting in “lenient” and “strict” rules

LULUCF accounting systems should provide credits for proven CO2 removals from new or enhanced sinks as a result of further policy intervention. Credits for such activities would result in CO2 removals from the atmosphere that could contribute to meeting, and thus should be counted towards, targets50.

The “strict” rules cases developed in this chapter reflect situations in which LULUCF credits such as those described above are provided. For calculation purposes, the quantity of LULUCF credits is set to zero in these cases – although some credits could occur. This is accurate because the resulting target emission level is the same and therefore it is not necessary to estimate the possible quantity of these LULUCF credits.

In the “lenient” case, on the other hand, we assume that credits are given for CO2 removals by sinks that are expected to occur anyway in the absence of additional policy (e.g. from forests existing prior to 1990). Given that these direct-human induced emission removals are anyway part of the baseline emissions,51 the use of such credits would increase the estimate of 2020 global emissions. In this assessment we call such credits “lenient LULUCF credits”. Specifically, we assume that “lenient LULUCF credits” of up to 0.8 GtCO2e per year in 2020 could be generated in the “lenient” cases shown in Figure 2. See Appendix 1 for details.

  50    For the same emission target these credits would allow correspondingly higher emissions in other sectors compared to the situation in which such LULUCF credits were not used to meet the target. In this case, from a global accounting sense, the final net emission level would be the same, assuming that target is met (i.e. would have a “net-zero” effect on the target)
  51    Or are considered by carbon cycle models as CO2-uptake by the terrestrial biosphere in response to elevated CO2 concentrations