Wednesday, February 18, 2009

Biofuels and Cropland Requirements

Today in my environmental science class we are working through a series of calculations to estimate the amount of cropland it would take to produce enough ethanol to satisfy American's thirst for oil. The average American uses about 25 barrels of oil per year. Some rough estimates:
-25 barrels is about 146,200,00 Btu
-It takes about 1124 gallons of gasoline to produce this equivalent in Btu
-To produce this Btu equivalent would take 1843 gallons of ethanol
-It take about 737 bushels of corn to produce this much ethanol
-It takes about 6.7 acres of land to produce this many bushels

So the average American needs 6.7 acres of corn producing land to satisfy their oil thirst. The rough estimates get more fun. Let's multiply the 6.7 acres of land needed by the number of Americans and we get somewhere around 2 billion acres. How many acres of cropland is there in America? About 435 million acres. The entire land area of the United States is 2.262 billion acres.

Environmental studies students at Lasell quickly start the see the issue with biofuels. While biofuels may help supplement our liquid fuel needs it certainly is not a solution. Where will the carrots (83,000 acres), strawberries (51,000 acres), and wheat (55,000,000 acres) grow?

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