Question 80 from UPSC CSE 2025 - Environme nt & Ecology

Question

Consider the following statements:
1. Of the two major ethanol producers in the world, i.e., Brazil and the United States of America, the former produces more ethanol than the latter.
2. Unlike in the United States of America where corn is the principal feedstock for ethanol production, sugarcane is the principal feedstock for ethanol production in Brazil.
Which one of the following is correct in respect of the above statements?

Accepted Answer

Correct Option: D. Statement I is not correct but Statement II is correct

Strategy: Focus on global ethanol production data—it's well-known that the United States is consistently the largest ethanol producer, not Brazil, thus invalidating Statement 1. Next, assess the feedstock: corn in the US and sugarcane in Brazil are standard textbook facts, confirming Statement 2 as correct. Therefore, choose the option that keeps only Statement 2 correct.

Key Info: Ethanol production is a key component of the biofuel industries in several countries, with the United States and Brazil accounting for the majority share globally (about 80%). The United States has led the world in ethanol output for several years, producing over 16 billion gallons annually, mainly from corn, owing to the country's vast corn cultivation and established agribusiness infrastructure. Brazil, the second-largest producer, yields around 8-9 billion gallons yearly, largely from sugarcane, using efficient fermentation processes.

Corn-based ethanol dominates in the US due to government incentives, the Renewable Fuel Standard (RFS), and abundant corn supplies. Conversely, Brazil's sugarcane-based ethanol benefits from a highly efficient conversion process, typically yielding a higher energy output per unit of input and helping achieve relatively low greenhouse gas emissions compared to corn-based ethanol.

Globally, feedstock choice is shaped by local agricultural patterns, energy policies, and climatic factors. Ethanol from sugarcane is prevalent in tropical nations, while temperate countries utilize starch-rich crops like corn. Ethanol is used as a fuel additive to reduce emissions and dependence on fossil fuels. Both countries blend ethanol with gasoline—Brazil's vehicles commonly run on high-ethanol blends or pure ethanol due to flexible-fuel vehicle technology, while the US usually uses 10% blends (E10) nationally, with E15 and E85 in some areas.

Answer

Option A: Both Statement I and Statement II are correct and Statement II explains Statement I

Answer

Option B: Both Statement I and Statement II are correct but Statement II does not explain Statement I

Answer

Option C: Statement I is correct but Statement II is not correct