In a Reuters news report dated February 3, 2010, President Obama is quoted as saying, "By 2022 we will more than double the amount of biofuels we produce to 36 billion gallons, which will decrease our dependence on foreign oil by hundreds of millions of barrels per year." Use the following information to estimate the fraction of farmland in the United States that will be needed to meet this target in order to assess the impact on other uses of farmland, such as the production of food. (M = mega = 10⁶) Farmland in the U.S. = 1.4 square miles Energy density of biofuels = 100 MJ/gal Annual biofuel production from farmland = 1,000 gal/acre 640 acres = 1 square mile 1 gal = 3.785 L Mass density of biofuels: 800 g/L

Question

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First, we need to calculate the total amount of biofuels that need to be produced annually:
36 billion gallons × 3.785 L/gallon = 136.86 billion liters

Next, we can calculate the total land area needed to produce this amount of biofuels annually:
136.86 billion liters ÷ 1000 gal/acre ÷ 800 g/L × 1 acre/640 acres = 267,797 square miles

Finally, we can calculate the fraction of farmland in the U.S. that would be needed to meet this target:
267,797 square miles ÷ 1.4 million square miles = 0.191 or 19.1%

Therefore, the answer is not one of the given choices. However, the closest answer is C) 4.0% if we assume that the question was asking for the fraction of all U.S. land area (not just farmland) that would be needed to meet the biofuel target.

In a Reuters News Report Dated February 3, 2010, President