It's dinnertime but there's no food in the house, so you get in your car and drive to the grocery store. You walk the aisles browsing for something to buy. You pick up chicken and a pre-made salad, then return home to enjoy your meal. Consider the ways your seemingly simple trip to the market affected the environment.
Driving to and from the store contributed carbon dioxide to the atmosphere. The electricity required to light the store was powered by coal, the mining of which ravaged an Appalachian ecosystem. The salad ingredients were grown on a farm treated with pesticides that washed into local streams, poisoning fish and aquatic plants (which help keep the air clean). The chicken was grown on a massive factory farm a long distance away, where animal waste produced toxic levels of atmospheric methane. Getting the goods to the store required trucks, trains and more trucks -- all of which emitted carbon.
Even the smallest human actions initiate environmental change. How we heat our homes and power our electronics, how we get around, what we do with our garbage, where our food comes from -- all of these put a strain on the environment beyond what it's designed to support.
Taken at a societal level, human behavior changes the environment in dramatic ways. The Earth's temperature has increased by one degree Fahrenheit since 1975 [source: National Geographic]. The polar ice caps are shrinking at a rate of 9 percent a decade [source: National Resources Defense Council].
We hurt the environment in more ways than you could possibly imagine. Misguided construction, irrigation and mining can deface the natural landscape and disrupt important ecological processes. Aggressive fishing and hunting can deplete entire stocks of species. Human migration can introduce alien competitors to native food chains. Greed can lead to catastrophic accidents and laziness to environmentally destructive practices.
So what are the worst offenders? Here are the top 10.