Are biofuels really friendly to the environment?

As the amount of fossil fuels, such as oil and coal, is decreasing, people are becoming aware of alternatives to them. One of the most notable alternative fuels is biofuel. However, biofuels arecontroversial, and some people claim that biofuels have good effects on the environment and people’s lives, and others claim that they have bad effects. There are two possibilities on biofuels: a good oneand bad one.
One good point of biofuels is security for energy. According to British Petroleum, oil will dry up in 40 year. When oil dry up, other fossil fuels, such as coal and natural gas arenot enough to provide energy for people all over the world. Therefore, people need to prepare new sources of energy, and people can use biofuels. Biofuels are very important and innovative in thatpeople can create them by cultivating plants. Thus, people do not have to worry about exhaustion of biofuels.
However, there are a lot of faults in biofuels. First, vast cultivated land isnecessary for crops which are materials of biofuels. In order to open out enormous cultivated land, people have to cut down huge forests. It leads to deforestation, and there will be less biodiversity.Moreover, forests absorb a large amount of CO2, which is a kind of greenhouse gas and causes global warming, and produce O2, which is essential for living things. For example, rain forests in Brazilproduce about 30 % of all O2 on the earth, but 10 times land as Tokyo has disappeared in the past 5 years. Therefore, when a lot of forests are changed into land for agriculture, it accelerates globalwarming and threatens extinction of lots of creatures.
Second, in order to cultivate a large amount of crops for biofuels, people need tremendous water. The use of water leads to a scarcity ofwater. For example, in both India and China, biofuel industry is growing so rapidly, and the amount of water for cultivating “biofuels” is increasing. Almost all sugar canes for biofuels depend on water...