Fig. 1: Global HFC-23 emissions and HCFC-22 production.

a Top-down global HFC-23 emissions (blue line) and uncertainties (blue shaded area; 1\(\sigma\), incorporating uncertainties due to the prior constraints, measurements, model representations of the data, calibration scale and HFC-23 lifetime, see Methods section) derived from Advanced Global Atmospheric Gases Experiment (AGAGE) data and the 12-box model (inferred emissions available in Supplementary Table 4). All other lines represent global (dashed) or sub-global (dotted) bottom-up estimates: developing countries emissions estimates (HCFC-22 production multiplied by an emissions factor (EF)) are shown in dark green; developed countries emissions obtained from United Nations Framework Convention on Climate Change (UNFCCC) reports are shown in black; the developing countries no abatement global total emissions estimates (sum of emissions from the unabated developing countries estimates and developed countries reports) are shown in orange; the developing countries with abatement global estimates are shown in green (equivalent to the developing countries no abatement estimates but with clean development mechanism (CDM) and post-2015 reports subtracted); the red dotted line is equivalent to the developing countries no abatement estimates, but with the maximum reported CDM abatement amount subtracted each year after 2011 (9.0 Gg yr\({}^{-1}\)), thus estimating the maximum possible legacy of the CDM. The hatched and cross-hatched areas represent the CDM and post-2015 abatement (Chinese and Indian reported emissions reductions combined), respectively. b Total HCFC-22 production (dashed orange line) from developing countries (dark green dotted line) and developed countries (black dotted line). All data points are shown as the mid-point of the respective year.