Third IMO Greenhouse Gas Study 2014

Scenarios for shipping emissions 2012–2050 139
Lastly, the decoupling of future use of fossil fuel from GDP is illustrated by the decline in the use of coal
and oil in some scenarios, shown in Figure 83. This is in line with the storylines of the lower RCP scenarios
(e.g. RCP2.6/3PD and RCP4.5).
Figure 83: Historical data to 2012 on global transport work for ship-transported coal
and liquid fossil fuels (billion tonne-miles) coupled with projections of coal and energy demand
driven by RCPs 2.6, 4.5, 6.0 and 8.5 by 2050
3.3.2 Projected CO 2 emissions
Using the model and input described above, this study has projected CO 2 emissions for 16 scenarios:
• four RCP/SSP-based scenarios of transport demand, disaggregated into cargo groups;
• for each of these four scenarios, one ECA/fuel mix scenario that keeps the share of fuel used in
ECAs constant over time and has a slow penetration of LNG in the fuel mix, and one that projects a
doubling of the amount of fuel used in ECAs and has a higher share of LNG in the fuel mix;
• for each of the eight combinations of demand and ECA scenarios, two efficiency trajectories, one
assuming an ongoing effort to increase the fuel-efficiency of new and existing ships after 2030,
resulting in a 60% improvement over the 2012 fleet average by 2050, and the other assuming a 40%
improvement by 2050.
The scenarios and their designations are summarized in Table 77.