MnrAq

Scenarios for shipping emissions 2012–2050 137
Substance GWP Notes
Table 76 – HFCs used on board ships
R-22 1,810 R-22 (chlorodifluoromethane) has been the dominant refrigerant in air
conditioners used on board ships. The production of R-22 has been phased
out under the Montreal Protocol in many countries. It is assumed that it is
used only in vessels built before 2000.
R134a 1,300 R134a (1,1,1,2-Tetrafluoroethane) is used as a replacement for R-22 in vessels
built from 2000 onwards.
R404a 3,700 R404a is a mixture of R125, R143a and R134a. It is used predominantly in
fishing vessels but also in freezing and cooling equipment in other vessels.
Assuming that ships built before 2000 have a 25-year lifetime, R-22 will have become obsolete in shipping by
2025. The study does not model that other HFCs will be phased out, that air conditioner leakage rates will
change or that other coolants will replace HFCs.
The emissions factors of other relevant substances are assumed to remain constant over time.
3.3 Results
3.3.1 Transport demand
The projections of GDP are shown in Figure 80, where SSP5 (associated in this study with RCP8.5) results in a
world GDP that is approximately seven times greater than present-day values by 2050 (at constant 2005 US$);
SSP3 (the lowest) projects GDP to triple in the same period.
Figure 80: Historical data to 2012 on global GDP (constant 2005 US$ billion/yr)
coupled with projections of GDP from SSP1 through to SSP5 by 2050