Environmental Engineering Reference
In-Depth Information
2.5
2
1.5
1
Extrapolating trends since ~1980-85
depending on data source
0.5
0
1950
1960
1970
1980
1990
2000
2010
2020
2030
Seaborne trade (tons)
Seaborne trade (ton-miles)
OECD HFO Int'l sales
Seaborne trade (trend since 1985)
World marine fuel (Eyring et al., 2005a)
Installed power
Figure 2.5
Global indices for seaborne trade, ship energy/fuel demand, and installed
power
and trade data discussed earlier. We compare world
eet trends in installed power (derived
from average power by year of build) with energy trends (work by Eyring et al. and fuel
sales), with trade-based historical data (tons and ton-miles). Activity-based energy results
for similar base years (2001 or 2002) are within close agreement (Corbett and Koehler,
2004; 2003; Eyring et al., 2005a). This allows us to index trends to nearly the same value
and year, to index trade-based trends similarly, and to compare these with trends in
installed power (Figure 2.5).
Three insights emerge from this global comparison. Extrapolating past data (with adjust-
ments) produces a range of trends that is bounded and reveals convergence around a set of
similar trends; in other words, while the range of growth may vary within bounds of a factor
of two, one cannot get 'any forecast one wants' out of the data. If we consider that global
trade and technology drivers mutually in
fl
uence future trends, then we may interpret con-
vergence within the bounds as describing a likely forecast of global shipping activity.
World shipping activity and energy use are on track to double from 2002 by about 2030
(~2015 if one considers seaborne trade since 1985, ~2050 if one considers Eyring et al.'s
BAU (business as usual) trend). Growth rates are not likely to be reduced without signi
fl
fi
cant
changes in freight transportation behavior and/or changes in shipboard technology.
Con
rming earlier discussion, trends in installed power are clearly coupled with trends
in trade and energy. This reinforces the analysis of installed power as a proxy for fore-
casting growth, not only for use in baseline inventory estimates.
Change in energy and emissions could be a modi
fi
ed growth curve from the growth
in cargo activity, depending on change in energy intensity and/or emissions through
fi
