Les émissions de R22 et de R134a sont 2 à 3 fois plus importantes en été (en anglais)

Dans un récent article publié dans PNAS, B. Xiang et al. présentent les résultats de mesures en altitude combinées à des mesures au sol concernant les émissions de R22 et de R134a.
In a recent article “Global emissions of refrigerants HCFC-22 and HFC-134a: unforeseen seasonal contributions” published in the Proceedings of the National Academy of Sciences, B. Xiang et al.  present the results of in situ observations of R22 and R134a taken from research aircraft over the Pacific Ocean in a 3-year span (2009-2012) combined with long-term ground observations from global surface sites.

The authors find that emissions of R134a are consistently higher compared with the United Nations Framework Convention on Climate Change (UNFCCC) inventory since 2000, by 60% more in recent years (2009-2012).

They also quantify recent seasonal emission patterns showing that summer emissions of HCFC-22 and HFC-134a are two to three times higher than winter emissions.

According to the authors, this unforeseen large seasonal variation indicates that unaccounted mechanisms controlling refrigerant gas emissions are missing in the existing inventory estimates.

Possible mechanisms enhancing refrigerant losses in summer are

(i) higher vapor pressure in the sealed compartment of the system at summer high temperatures
(ii) more frequent use and service of refrigerators and air conditioners in summer months.

The results suggest that engineering (e.g., better temperature/vibration-resistant system sealing and new system design of more compact/efficient components) and regulatory (e.g., reinforcing system service regulations) steps to improve containment of these gases from working devices could effectively reduce their release to the atmosphere.