 Traffic congestion, deaths and injuries from car accidents, air pollution, and global warming are unintended consequences of the invention and large scale adoption of the automobile.Hospital infections are the unexpected side-effect of antibiotic resistance, and even human overpopulation is the side effect of various technological (i.e., agricultural and industrial) revolutions.Because of the complexity of ecosystems, deliberate changes to an ecosystem or other environmental interventions will often have (usually negative) unintended consequences.