What is a problem that is created by ethanol as a biofuel?

A problem that is caused by use of ethanol as a biofuel is that crops which could be used to feed people are used to provide raw materials for biofuels. This could cause food shortage or increase the price of food.

In addition, large tracts of land have to be used to grow large amounts of crops to produce ethanol. There is concern that more land will have to be cleared in order to grow more crops to satisfy increased demand. This could lead to the destruction of important ecosystems and cause erosion.