The large contribution of projected HFC emissions to future climate forcing

Abstract

The consumption and emissions of hydrofluorocarbons (HFCs) are projected to increase substantially in the coming decades in response to regulation of ozone depleting gases under the Montreal Protocol. The projected increases result primarily from sustained growth in demand for refrigeration, air-conditioning (AC) and insulating foam products in developing countries assuming no new regulation of HFC consumption or emissions. New HFC scenarios are presented based on current hydrochlorofluorocarbon (HCFC) consumption in leading applications, patterns of replacements of HCFCs by HFCs in developed countries, and gross domestic product (GDP) growth. Global HFC emissions significantly exceed previous estimates after 2025 with developing country emissions as much as 800% greater than in developed countries in 2050. Global HFC emissions in 2050 are equivalent to 9 -19% (CO 2-eq. basis) of projected global CO 2 emissions in business-as-usual scenarios and contribute a radiative forcing equivalent to that from 6 -13 years of CO 2 emissions near 2050. This percentage increases to 28 -45% compared with projected CO 2 emissions in a 450-ppm CO2 stabilization scenario. In a hypothetical scenario based on a global cap followed by 4% annual reductions in consumption, HFC radiative forcing is shown to peak and begin to decline before 2050.HCFC consumption ͉ radiative forcing ͉ scenarios

Earth’s Climate System

“…Velders et al (2009) project the RF of climate due to HFCs could be 0.4 W m −2 by mid-century, considerably larger than the RF due to HFCs considered by IPCC (2013). The primary reason for this difference is their projection of considerably larger growth in the atmospheric abundance of HFC-125 (formula CHF 2 CF 3 ; lifetime = 28 years; GWP = 3170) than in the scenarios used to guide the IPCC climate models.…”

“…1.4), which is about 1 % of the total RF of climate due to all anthropogenic GHGs. Nonetheless, there is concern the RF of climate of these compounds could rise in the future (IPCC/TEAP 2005; Velders et al 2009;Zhang et al 2011). The Doha amendment, adopted in December 2012, added nitrogen trifluoride (NF 3 ) to the list of GHGs in the Kyoto Protocol.…”

Overview of the findings from measurements of halogenated compounds at Gosan (Jeju Island, Korea) quantifying emissions in East Asia

“…HCFC-22 has been the dominant interim-replacement for CFCs in refrigerant applications (Velders et al 2009;Wan et al 2009; also see http://www.afeas.org). And while consumption of HCFC-22 has effectively been phased out in most developed countries and replaced with HFC blends, it continues to be widely used in developing countries such as China and Korea (Montzka et al 2009).…”

Valence electronic structure and photofragmentation of 1,1,1,2-tetrafluoroethane (CF3-CH2F)

“…The use of hydrofluorocarbons (HFCs) such as fluorinated ethanes has increased as a less ozone (O 3 )-depleting alternative to chlorofluorocarbons (CFCs, commercially better known as freons) and hydrochlorofluorocarbons (HCFCs), which are planned to be phased out as a result of the Montreal Protocol on Substances That Deplete the Ozone Layer [3][4][5][6][7][8]. These synthetic gases have been used as refrigerants, propellants, blowing agents, and solvents.…”

“…As an example, in the European Union, the use of 1,1,1,2-tetrafluoroethane in automobile conditioning systems will be phased out between the years 2011 and 2017 [11]. The potential future climate contribution of HFCs has raised interest from the Montreal Protocol Parties, but the global demand for HFCs is expected to increase in developed and developing countries, especially because of a lack of regulations (see Velders et al [5], Montzka et al [8], and references therein).…”