tpo 22: replacing gasoline with ethanol

In this set of material, reading passage was about replacing gasoline with ethanol and disadvantages of this replacement. The listening passage was a lecture by a professor who believes that ethanol is a good alternative for gasoline and none of the reasons presented in the reading passage are convincing.

First, using ethanol releases the same amount of carbon dioxide that burning other fuels does. Existence of greenhouse gases in the atmosphere can lead to global warming and carbon dioxide is one. The professor agrees with this fact but he also believes that the process of growing plants in order to extract ethanol contacts with CO2. Plants have this ability to absorb carbon dioxide and use it as their food.

Second, corn and sugar cane that are mainly the source plants for ethanol are also are being used for another uses like feeding animals, So if they want to make ethanol from current plants a substantial resource of their food vanishes. However; professor mentions that ethanol can come from parts of plant sell that are not eaten by animals, so it doesn't have any contradicts with farmers.

Third, the price of ethanol now is much higher than gasoline because it's not generally produced. Whenever a product is in high demand and is produced greatly, as a result the price reduces. So he believes that the price would not be an issue, and also no more subsidies are required for it. Because it drops 40 percent after it gets produced in large scales.