Cars are a huge contributor to Global Warming. Cars emit a lot of Greenhouse Gases, and consume a lot of fuel. In America most citizens will get a big truck, or a popular Hummer which at the best will get 20 mpg.  In fact, America is so bad in gas conservation that the average mpg in an automobile has decreased in America since the automobile was invented. Aside from the fact that you use a lot of oil to go a little way, it is very interesting to know that only fifteen percent of the gas you fill up gets used to move your car. The rest is used for the other accessories such as heat and air-conditioning.

          There are many solutions to making automobiles more efficient to decrease the effect of Global warming. First Americans should buy fuel-efficient cars. Hybrid cars would be a good choice, they usually get about 60 mpg. If you buy a fuel-efficient car like the hybrid then you will find that you are paying much less for gas. Another idea is to carpool. People should minimize their driving so that their emissions are less, and that they are saving gas. In Washington D.C on the freeway, if you have three or more people in your car, then you will get to go in the fast lane as a reward.

Other Human Causes are industry and agriculture pollution.