Third IMO Greenhouse Gas Study 2014

140 Third IMO GHG Study 2014
Table 77 – Overview of assumptions per scenario
Scenario RCP scenario SSP scenario Fuel mix
(LNG, ECA)
1 RCP8.5 SSP5 high LNG/extra ECA High
2 RCP6.0 SSP1 high LNG/extra ECA High
3 RCP4.5 SSP3 high LNG/extra ECA High
4 RCP2.6 SSP4 high LNG/extra ECA High
5 RCP8.5 SSP5 high LNG/extra ECA Low
6 RCP6.0 SSP1 high LNG/extra ECA Low
7 RCP4.5 SSP3 high LNG/extra ECA Low
8 RCP2.6 SSP4 high LNG/extra ECA Low
9 RCP8.5 SSP5 low LNG/no ECA High
10 RCP6.0 SSP1 low LNG/no ECA High
11 RCP4.5 SSP3 low LNG/no ECA High
12 RCP2.6 SSP4 low LNG/no ECA High
13 (BAU) RCP8.5 SSP5 low LNG/no ECA Low
14 (BAU) RCP6.0 SSP1 low LNG/no ECA Low
15 (BAU) RCP4.5 SSP3 low LNG/no ECA Low
16 (BAU) RCP2.6 SSP4 low LNG/no ECA Low
Efficiency
improvement
2050
The resulting projections of CO 2 emissions are presented graphically in Figure 84 and in tabular form in
Table 78. The average emissions growth across all scenarios in 2020 amounts to 7% of 2012 emissions. For
2030, the average emissions increase is 29% and for 2050 95%. Some scenarios have higher growth, such as
those with high economic growth (SSP5) and high fossil fuel consumption (RCP8.5), while the scenarios with
low economic growth (SSP3) and moderate fossil fuel use (RCP4.5) have the lowest emissions growth. All BAU
scenarios show an increase in emissions, ranging from 50% to 250% in 2050.
Scenarios with high improvements in efficiency after 2030 (1–4 and 9–12) exhibit either decelerating emissions
growth after 2035 or 2040 or a downward trend after those years, when combined with moderate economic
growth and decreasing fossil fuel use. Figure 84 shows that in many cases the lines representing high-efficiency
scenarios cross the lines of low-efficiency but higher growth scenarios. This suggests that, to some extent,
more ambitious improvements in efficiency can offset higher transport demand.