Projecting future HFC-23 emissions 1Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
21 Dec 2011
2Global Monitoring Division, ESRL, NOAA, Boulder, Colorado, USA
3Eindhoven Centre for Sustainability, Technical University Eindhoven, Eindhoven, Netherlands
Received: 11 Jul 2011 – Published in Atmos. Chem. Phys. Discuss.: 16 Aug 2011 Abstract. A Reference Case (RC) scenario for emissions of HFC-23 from co-production
during HCFC-22 manufacture over the next 25 years is presented. Offered as a
template rather than a prediction, this model projects current production
practices and existing abatement frameworks to yield insights into how
atmospheric composition and radiative forcing might change with and without
additional efforts to constrain HFC-23 emissions.
Revised: 06 Nov 2011 – Accepted: 07 Dec 2011 – Published: 21 Dec 2011
Assuming that no additional abatement measures are implemented, emissions
for year 2035 in this Reference Case would rise to 24 ktonnes yr−1,
(cf., 8.6 ktonnes yr−1 in 2009), the atmospheric abundance of HFC-23
would rise to 50 ppt, which is a 121 % increase over the 2009 observed
abundance, and HFC-23 would be expected to contribute a radiative forcing of
9 mW m−2 (cf., 4 mW m−2 in 2009). Under such a scenario, the
HFC-23 emission growth rate would be a continuation of the historical trend
of ∼0.2 ktonnes yr−2 until 2030, after which the growth is
projected to quadruple as the Montreal Protocol phase-out of HCFC production
for dispersive use concludes and HFC-23 thermal decomposition in the
projects of the Clean Development Mechanism (CDM) comes to a scheduled end
while growth in the production of HCFC-22 for feedstock use continues to
climb with projected GDP growth.
Two opposite variations regarding the future renewal of CDM projects are
examined for their impact on projected emissions and abundance, relative to
the Reference Case scenario.
Citation: Miller, B. R. and Kuijpers, L. J. M.: Projecting future HFC-23 emissions, Atmos. Chem. Phys., 11, 13259-13267, doi:10.5194/acp-11-13259-2011, 2011.