When war comes to mind, most people think about missiles hitting the Earth or the amount of human lives that are lost because of it. The ordinary person doesn't think about how warfare can affect the environment. War can have a huge detrimental effect on the natural environment. Uranium is a component of missiles used in war, but they contain carcinogenic components that end up in water streams. This can lead to health issues for humans and animals alike. In some places perchlorate, a harmful chemical, is found in groundwater sources near places where weapons are fabricated. In 2012 the US Department of Defense emitted 70 million metric tons of CO2, and used 4.6 million gallons of fuel. This all adds up and leads to more CO2 emissions.