This is different from achieving net zero GHG 
emissions, where metric-weighted anthropogenic GHG emissions (see 
Cross-Section Box.1) equal CO2 removal (high conﬁdence). Emissions 
pathways that reach and sustain net zero GHG emissions deﬁned by the 
100-year global warming potential imply net negative CO2 emissions 
and are projected to result in a gradual decline in surface temperature 
after an earlier peak (high conﬁdence). While reaching net zero CO2 or net 
zero GHG emissions requires deep and rapid reductions in gross 
emissions, the deployment of CDR to counterbalance hard-
to-abate residual emissions (e.g., some emissions from agriculture, 
aviation, shipping, and industrial processes) is unavoidable (high 
conﬁdence). {WGI SPM D.1, WGI SPM D.1.1, WGI SPM D.1.8; WGIII SPM C.2, 
WGIII SPM C.3, WGIII SPM C.11, WGIII Box TS.6; SR1.5 SPM A.2.2}
In modelled pathways, the timing of net zero CO2 emissions, 
followed by net zero GHG emissions, depends on several 
variables, including the desired climate outcome, the mitigation 
strategy and the gases covered (high conﬁdence). Global net zero 
CO2 emissions are reached in the early 2050s in pathways that limit 
warming to 1.5°C (>50%) with no or limited overshoot, and around 
the early 2070s in pathways that limit warming to 2°C (>67%). While 
non-CO2 GHG emissions are strongly reduced in all pathways that limit 
warming to 2°C (>67%) or lower, residual emissions of CH4 and N2O 
and F-gases of about 8 [5–11] GtCO2-eq yr-1 remain at the time of 
134 Net zero GHG emissions deﬁned by the 100-year global warming potential. See footnote 70.
135 See Section 3.3.3 and 3.4.1.
net zero GHG, counterbalanced by net negative CO2 emissions.