Environmental science is an interdisciplinary academic field that integrates physical, biological and information sciences(including ecology, biology, physics, chemistry, plant science, zoology, mineralogy, oceanography, limnology, soil science, geology and physical geography (geodesy), and atmospheric science) to the study of the environment, and the solution of environmental problems. Environmental science emerged from the fields of natural history and medicine during the Enlightenment. Today it provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems.
Ecology is not a synonymum for environtmental.
Source : Wikipedia : Environmental science