Exploring Synergistic GHG Emissions Mitigation Potential and Costs of Room Air Conditioners

This study explores the potential of synergistically
reducing direct
(refrigerant) and indirect (electricity) greenhouse gas (GHG) emissions
in the global room air conditioning (RAC) sector, based on 80% of
global RAC manufactured in China. Three scenarios are evaluated: Business-as-usual
(BAU) based on maintaining refrigerant and energy efficiency levels
from 2021 China RAC sales shares, Kigali Amendment compliant with
10% energy efficiency improvement by 2025 (KAE), and accelerated refrigerant
transition and energy efficiency improvement (ATE). Each scenario
considers the costs of refrigerant and efficiency measures for export
market groups based on Kigali Amendment classifications. BAU predicts
around 1 Gt CO2-eq average annual global RAC emissions
(2022–2060). Cumulative emission reductions in China’s
RAC manufacturing under KAE and ATE are 12.2 and 17.2 Gt CO2-eq A5II and A5I (except China), presenting cost-effective abatement
measures, with average costs of -$51.4 and -$68.8/t CO2-eq in KAE and ATE. Cumulative average abatement costs are around
$18 and $4/t CO2-eq globally. KAE and ATE scenarios would
avoid surface temperature rises of 0.023 (±0.002) °C and
0.027 (±0.003) °C, respectively, versus BAU. Collaboration
between China and importing countries is urged to enhance energy efficiency
in RACs traded, ensuring sustainable mitigation aligned with the Kigali
Amendment.