THE ENVIRONMENT Necessities of Life Human beings need food, water, and air, which are all necessary for survival. People cannot live without food to eat and oxygen to breathe. When it is cold, they need heat, clothes, and places to live. Since 1850, both the population and industry have increased very rapidly. There are several kinds of pollution: air, water, and land. Industry causes air pollution. Chemicals also cause land and water pollution. Life on earth depends on the environment. Obama seeks to exploit GOP divide on renewable energy (CBS News) There was some big talk on energy Tuesday on the campaign trail. President Obama talked wind power and Mitt Romney said if he is elected, America will be so energy independent by the end of his second term that we'll no longer have to buy oil from the Middle East and Venezuela. The president has talked about wind energy at every stop on this Iowa bus trip. Former Governor Romney focused on oil and coal. Both men are trying to draw attention to an issue that could sway the race in several battleground states -- energy. At a wind farm in Haverhill, Iowa, President Obama touted his support for a valuable tax break for wind producers, a break Romney opposes. "He's called these sources of energy imaginary. Iowa is home to the nation's largest wind sector, employing 6,000-7,000 people and providing 20 percent of the state's energy. So Republican leaders in Iowa were startled when the Romney campaign came out against renewing the tax credit when it expires later this year.