Sugarcane ethanol: Contributions to climate change - BAFF

Chapter 7
�e three categories added together lead to a biomass supply potential of up to about
500 EJ.
Energy demand models calculating the amount of biomass used if energy demands are
supplied cost-e�ciently at di�erent carbon tax regimes, estimate that in 2050 about 50-250
EJ/yr of biomass are used. At the same time, scenario analyses predict a global primary energy
use of about 600 – 1040 EJ/yr in 2050 (the two right columns of Figure 2). Keep in mind that
food demand of around 9 billion people in 2050 are basically met in those scenario’s.
EJ/year
1,600
1,000
800
600
400
200
0
High
range
Medium
range
Low range
Biomass potentials
review studies
'ultimate' technical potential
Learning in
agricultural
technology
No exclusion
With exclusion
of areas
Surplus forestry
Residues
Biomass potentials
analysis this study
Range
studies
Modelled bioenergy
demand
Figure 2. Comparison of biomass supply potentials in the review studies and in this study with the
modelled demand for biomass and the total world energy demand, all for 2050 (Dornburg et al.,
2008). EJ = Exajoule (current global energy use amounts about 470 EJ at present). The first bar from
the left represents the range of biomass energy potentials found in different studies, the second
presents the results generated in (Dornburg et al., 2008), taking a variety of sustainability criteria
into account (such as water availability, biodiversity protection and soil quality), the third bar shows
currently available estimates of biomass demand for energy from long term scenario studies and the
fourth bar shows the range of projections of total global energy use in 2050.
162 Sugarcane ethanol
Range
WEA
Total world
energy demands