226
Based on this, the amount of feedstock that would be needed to expand biofuels
to account for 20% or 50% of gasoline and diesel use can be calculated. The result
is that in order to offset 20% of gasoline and diesel use in 2008–2010, 41.5% of
global coarse grain, 110% of vegetable oil, and 79% of sugarcane production would
have been needed. To offset 50% of gasoline and diesel use, 103.8% of coarse grain,
275% of vegetable oil, and 500% of sugarcane production would have been needed.
Thus, the level of biofuel feedstock production and technology in 2008-2010 was
not sufficient to replace 50% of either diesel or gasoline, since more than the entire
amount of global feedstock production would have been required. Even to replace
20% of diesel or gasoline would have required much larger amounts of feedstock.
By 2020, it is projected that both feedstock production and the share of biofuel
in gasoline and diesel will increase, because of increased productivity and stronger
biofuel mandates. It appears that the percentage of biofuel feedstocks needed to
replace 20% or 50% of gasoline and diesel would decrease to some extent.
Nevertheless, a very large amount of feedstock would still be necessary to replace
20% of gasoline and diesel. To replace 50% of gasoline would still require more
than half of the total production of coarse grains, and to replace 50% of diesel, even
double the 2020 global vegetable oil production would not be enough. To be sure,
technological advances and increases in yields may improve this situation to some
extent, but the bigger picture is that there is a fundamental limit to how much biofuels can replace gasoline and diesel, considering that expansion of global biofuel
production is constrained by a scarcity of farmland which will be needed to feed an
increasing global population.
According to the FAO, to meet the needs of an expanding global population and
adapt to changing consumption patterns, the world’s food production will need to
increase considerably over the coming decades, growing 70% above the level of
2009 by 2050 to feed an estimated additional two billion people. Much of this will
need to be met by rising yields, although one study found that many biofuel feedstock crop yields have been overestimated, so that there might not be much room to
increase them, and also rising yields may lead to environmental pressures (Johnston
et al. 2009). The FAO says there is some room to expand biofuel feedstock production, but many of these potential new production areas are far from areas where
biofuels would be consumed and not necessarily suited for the crops in the highest
demand. Thus, most production growth would probably have to occur on existing
agricultural land (FAO 2011).
Water shortages will also be a concern, and this issue was examined by FAO
(2011). FAO’s report carefully avoided concluding that there is not enough water for
biofuels, but rather explained that there will be increased competition for water, as
well as land, among different uses including food and fuel. A study by SEI examining the water energy and food nexus calculated that completely replacing fossil
transport fuels would require 30 million barrels of ethanol and 23 million barrels of
biodiesel per day, and only 10% of the required ethanol would require an additional
600 km
3
of water per year, which is much more than the global consumptive combined municipal and industrial water use (Hoff 2011, 19). Water is needed not only
for the additional feedstock production but also for the fuel refining process. Thus,
M. Elder and S. Hayashi
Based on this, the amount of feedstock that would be needed to expand biofuels
to account for 20% or 50% of gasoline and diesel use can be calculated. The result
is that in order to offset 20% of gasoline and diesel use in 2008–2010, 41.5% of
global coarse grain, 110% of vegetable oil, and 79% of sugarcane production would
have been needed. To offset 50% of gasoline and diesel use, 103.8% of coarse grain,
275% of vegetable oil, and 500% of sugarcane production would have been needed.
Thus, the level of biofuel feedstock production and technology in 2008-2010 was
not sufficient to replace 50% of either diesel or gasoline, since more than the entire
amount of global feedstock production would have been required. Even to replace
20% of diesel or gasoline would have required much larger amounts of feedstock.
By 2020, it is projected that both feedstock production and the share of biofuel
in gasoline and diesel will increase, because of increased productivity and stronger
biofuel mandates. It appears that the percentage of biofuel feedstocks needed to
replace 20% or 50% of gasoline and diesel would decrease to some extent.
Nevertheless, a very large amount of feedstock would still be necessary to replace
20% of gasoline and diesel. To replace 50% of gasoline would still require more
than half of the total production of coarse grains, and to replace 50% of diesel, even
double the 2020 global vegetable oil production would not be enough. To be sure,
technological advances and increases in yields may improve this situation to some
extent, but the bigger picture is that there is a fundamental limit to how much biofuels can replace gasoline and diesel, considering that expansion of global biofuel
production is constrained by a scarcity of farmland which will be needed to feed an
increasing global population.
According to the FAO, to meet the needs of an expanding global population and
adapt to changing consumption patterns, the world’s food production will need to
increase considerably over the coming decades, growing 70% above the level of
2009 by 2050 to feed an estimated additional two billion people. Much of this will
need to be met by rising yields, although one study found that many biofuel feedstock crop yields have been overestimated, so that there might not be much room to
increase them, and also rising yields may lead to environmental pressures (Johnston
et al. 2009). The FAO says there is some room to expand biofuel feedstock production, but many of these potential new production areas are far from areas where
biofuels would be consumed and not necessarily suited for the crops in the highest
demand. Thus, most production growth would probably have to occur on existing
agricultural land (FAO 2011).
Water shortages will also be a concern, and this issue was examined by FAO
(2011). FAO’s report carefully avoided concluding that there is not enough water for
biofuels, but rather explained that there will be increased competition for water, as
well as land, among different uses including food and fuel. A study by SEI examining the water energy and food nexus calculated that completely replacing fossil
transport fuels would require 30 million barrels of ethanol and 23 million barrels of
biodiesel per day, and only 10% of the required ethanol would require an additional
600 km
3
of water per year, which is much more than the global consumptive combined municipal and industrial water use (Hoff 2011, 19). Water is needed not only
for the additional feedstock production but also for the fuel refining process. Thus,
M. Elder and S. Hayashi