Fig. 1: Emissions of CFC-11 and HFC-23 since 1990. | Nature Communications

Fig. 1: Emissions of CFC-11 and HFC-23 since 1990.

From: Unfinished business after five decades of ozone-layer science and policy

Fig. 1

a CFC-11 emissions with estimated 1σ error bars inferred from two different global data sets (set 1 (blue line) is from the AGAGE network, whereas set 2 (green) is from the NOAA network). Also shown are illustrative projections of emissions assuming no production outside of the Montreal Protocol and using different assumptions about bank sizes and release rates (blue and cyan lines from ref. 21, which assumes about 4.3–4.9% bank release rates/year, whereas pink lines include larger banks within the range of ref. 8, adopting 3–3.5%/year). Black horizontal lines depict averaged values for the data for 2004–2013 and for 2014–2016 as in ref. 4; the red arrow highlights the unexpected increase in emissions after 2013, indicating likely extra production. Black dotted and dash-dotted lines with arrows illustrate the dependence of the total discrepancy between inferred emissions from data vs. expected values from the illustrative banks. Adapted from Figs. 1–4 of ref. 21. b HFC-23 emissions with estimated 1σ error bars inferred from two different data sets (sets 2 (pink) and 3 (blue, updated from pink in ref. 12) are from the AGAGE network, whereas set 1 (green) is from the NOAA network, along with emissions based on national reports to the UNFCCC and Montreal Protocol Multi-Lateral Fund (MLF) through 2015 (light blue dashed line), and emissions expected based on national reports to the UNFCCC plus national policies (teal green dash-dotted line) described in ref. 12. Solid black lines with arrows highlight recent discrepancies between inferred emissions from data vs. expected values from international and national policies. Adapted from Figs. 2–7 of ref. 21, updated using ref. 12.

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