Tower Gardens Photo Journal

A couple of ways that humans have altered the environment is by global warming, chemical fertilizers, cutting down trees and large scale farming. Sustainability when referring to the environment means is the ability to maintain the qualities that are valued in the physical environment. Threats to these aspects of the environment mean that there is a risk that these things will not be maintained. An environmental system as a system where life interacts with the various abiotic components found in the atmosphere, hydrosphere, and lithosphere. Environmental systems also involve the capture, movement, storage, and use of energy. The First Law of Thermodynamics. The first law of thermodynamics, also known as Law of Conservation of Energy, states that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another. Systems can be open or closed to exchanges of matter, energy, or both. A systems analysis determines what goes into, what comes out of, and what has changed within a given system. Environmental scientists use systems analysis to calculate inputs to and outputs from a system and its rate of change. If there is no overall change, the system is in steady state. Changes in one input or output can affect the entire system. Variation in environmental conditions, such as temperature or precipitation, can affect the types and numbers of organisms present. Short-term and long-term changes in Earth's climate also affect species distributions. Environmental justice is the fair treatment and meaningful involvement of all people in the community. Philadelphia Water is committed to a balanced "land-water-infrastructure" approach to achieve its watershed management goals. Where appropriate, this method includes infrastructure-based approaches but focuses on implementation of a range of land-based stormwater management techniques and physical reconstruction of aquatic habitats.