Dr. Pimentel estimates the current ERoEI of corn-ethanol as 0.8.  In comparison, current calculations of the ERoEI of oil reveal an impressive ratio of 3:1.  Of course, this number is miniscule in comparison to the 1940’s when only 1 barrel of oil was required to extract 50 – 100 barrels of oil.   The reason for the gradual decrease in oil’s ERoEI has been the increasing amount of energy needed to be used to extract an increasingly scarce natural resource.  However these calculations only take into account the technology and manpower directly required to discover, mine, process, and transport oil.   They do not take into account the costs incurred in securing and defending access to oil fields that are becoming more and more highly contested.  

Though this is controversial, today much of the US’s foreign policy initiative is directed towards securing our oil interests in the Middle East. The government expenses on just the Iraq war have exceeded over 400 billion dollars. In addition, Linda Bilmes of Harvard University, states that if the war continues for another 5 years the total cost will amount to 1.4 trillion dollars. Though it is debatable how much of this money is directly used to secure oil interests, should we include this entire amount in the calculations of the ERoEI of oil? Should we include the 82 billion dollars spent on the first gulf war defending the oil fields in Kuwait?   In addition, China is emerging as a major oil consumer and military superpower.  Could the future bring us a major direct or indirect conflict with China over oil?  Should we take the costs of such a conflict into account when discussing energy alternatives?

Dr. Pimentel has provided us with a very in depth analysis of the energy balance associated with the production and transport of ethanol.   Estimation of the true cost of oil may benefit from a similarly in depth analysis that takes into account the political and military costs of our addiction.