World Energy Outlook 2006

200 EJ (4 800 Mtoe) of biomass production based on perennial crops could be
developed at a cost of $2 per GJ (Hoogwijk et al., 2005; Rogner et al., 2000).
In total, biomass potential from all sources could be as high as 1 100 EJ (over
26 000 Mtoe), though a more realistic assessment based on slower rates of
improvement in yields is 250 EJ to 500 EJ (6 000 to 12 000 Mtoe). A
mid-range estimate of 400 EJ would require about one-fifth of the world’s
existing agricultural land to be turned over to biomass energy production,
equal to about 8% of the world’s surface land area. World biomass energy
production in 2004 amounted to about 50 EJ (1 170 Mtoe). Soil, water and
nutrient constraints would reduce this potential.
These estimates are sensitive to assumptions about crop yields and the amount
of land that could be made available for the production of biomass for energy
uses, including biofuels. Critical issues include the following:
� Competition for water resources: Although the estimates cited above
generally exclude irrigation for biomass production, it may be necessary
in some countries where water is already scarce.
� Use of fertilizers and pest control techniques: Improved farm
management and higher productivity depend on the availability of
fertilizers and pest control. The heavy use of fertilizer and pesticides could
harm the environment.
� Land-use: More intensive farming to produce energy crops on a large
scale may result in losses of biodiversity. Perennial ligno-cellulosic crops
are expected to be less pernicious than conventional crops such as cereals
and seeds. More intensive cattle-raising could also be necessary to free up
grassland currently used for grazing.
� Competition with food production: Increased biomass production for
biofuels could drive up land and food prices, with potentially adverse
consequences for poor households. On the other hand, rising prices could
benefit poor farmers.
The share of the world’s arable land used to grow biomass for biofuels is
projected to rise from 1% at present to 2.5% in 2030 in the Reference Scenario
and 3.8% in the Alternative Policy Scenario, on the assumption that biofuels
are derived solely from conventional crops (Table 14.7). The amount of arable
land needed in 2030 is equal to more than that of France and Spain in the
Reference Scenario and to that of all the OECD Pacific countries – including
Australia – in the Alternative Policy Scenario. If second-generation
technologies based on ligno-cellulosic biomass were widely commercialised
before 2030, arable land requirements could be much less per unit of biofuels
output. In a Second-Generation Biofuels Case, ligno-cellulosic based
technologies are assumed to be introduced on a large scale, pushing the share
of biofuels in transport demand globally to 10% in 2030 compared with 5%
414 World Energy Outlook 2006 - FOCUS ON KEY TOPICS