9unit13Environmentalscience

1、Environmental scienceBlue Marble composite images generated by NASA in 2001 (left) and 2002 (right).Environmental science is an expression encompassing the wide range of scientific disciplines that need to be brought together to understand and manage the natural environment and the many interactions

2、 among physical, chemical, and biological components. Environmental Science provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems.1 Individuals may operate as Environmental scientists or a group of scientists may work together pooling their indivi

3、dual skills. The most common model for the delivery of Environmental science is through the work of an individual scientist or small team drawing on the peer-reviewed, published work of many other scientists throughout the world.The role of environmental scienceThe work of Environmental Science desc

4、ribes the environment, interprets the impact of human actions (anthropogenic effects) on terrestrial and aquatic ecosystems, and develops strategies for restoring ecosystems. In addition, environmental scientists help planners develop and construct buildings, transportation corridors, and utilities

5、that protect water resources and reflect efficient and beneficial land use.2. Due to the interdisciplinary nature of environmental science, teams of professionals commonly work together to conduct environmental research or to produce Environmental Impact Statements. Other professional organizations

6、engender work in environmental science and aid in communication among the diverse sciences.Since most environmental issues deal with human activities, study of economics, law and social sciences are often applied in conjunction with environmental science.Environmental science encompasses issues such

7、 as climate change, conservation, biodiversity, water quality, groundwater contamination , soil contamination, use of natural resources, waste management, sustainable development, disaster reduction, air pollution, and noise pollution.While the environment has been studied for at least as long as th

8、ere has been science, the recent interest in putting the pieces of understanding together to study environmental systems has come alive as a substantive, active field of scientific investigation starting in the 1960s and 1970s. This has been driven by the need for a large multi-disciplined team to a

9、nalyze complex environmental problems, the arrival of substantive environmental laws requiring specific environmental protocols of investigation, and growing public awareness of a need for action in addressing environmental problems.ComponentsAtmospheric sciences examine the phenomenology of the Ear

10、th's gaseous outer layer with emphasis upon interrelation to other systems. Atmospheric sciences comprises meteorological studies, greenhouse gas phenomena, atmospheric dispersion modeling of airborne contaminants,34 sound propagation phenomena related to noise pollution, and even light pollutio

11、nTaking the example of the global warming phenomena, physicists create computer models of atmospheric circulation and infra-red radiation transmission, chemists examine the inventory of atmospheric chemicals and their reactions, biologists analyze the plant and animal contributions to carbon dioxide

12、 fluxes, and specialists such as meteorologists and oceanographers add additional breadth in understanding the atmospheric dynamics.Ecology studies typically analyse the dynamics of biological populations and some aspect of their environment. These studies might address endangered species, predator/

13、prey interactions, habitat integrity, effects upon populations by environmental contaminants, or impact analysis of proposed land development upon species viability.An interdisciplinary analysis of an ecological system which is being impacted by one or more stressors might include several related en

14、vironmental science fields. For example one might examine an estuarine setting where a proposed industrial development could impact certain species by water pollution and air pollution. For this study biologists would describe the flora and fauna, chemists would analyze the transport of water pollut

15、ants to the marsh, physicists would calculate air pollution emissions and geologists would assist in understanding the marsh soils and bay muds.Environmental chemistry is the study of chemical alterations in the environment. Principal areas of study include soil contamination and water pollution. Th

16、e topics of analysis involve chemical degradation in the environment, multi-phase transport of chemicals (for example, evaporation of a solvent containing lake to yield solvent as an air pollutant), and chemical effects upon biota.As an example study, consider the case of a leaking solvent tank whic

17、h has entered the soil upgradient of a habitat of an endangered species of amphibian. Physicists would develop a computer model to understand the extent of soil contamination and subsurface transport of solvent, chemists would analyze the molecular bonding of the solvent to the specific soil type an

18、d biologists would study the impacts upon soil arthropods, plants and ultimately pond dwelling copepods who are the food of the endangered amphibian.Geosciences includes environmental geology, environmental soil science, volcanic phenomena and evolution of the Earth's crust. In some classificati

19、on systems it can also embrace hydrology including oceanography.As an example study of soils erosion, calculations would be made of surface runoff by soil scientists. Hydrologists would assist in examining sediment transport in overland flow. Physicists would contribute by assessing the changes in l

20、ight transmission in the receiving waters. Biologists would analyze subsequent impacts to aquatic flora and fauna from increases in water turbidity.Regulations driving the studiesIn the U.S. the National Environmental Policy Act (NEPA) of 1969 set forth requirements for analysis of major projects in

21、 terms of specific environmental criteria. Numerous state laws have echoed these mandates, applying the principles to local scale actions. The upshot has been an explosion of documentation and study of environmental consequences before the fact of development actions.One can examine the specifics of

22、 environmental science by reading examples of Environmental Impact Statements prepared under NEPA such as: Wastewater treatment expansion options discharging into the San Diego/Tiajuana Estuary, Expansion of the San Francisco International Airport, Development of the Houston, Metro Transportation system, Expansion of the metropolitan Boston MBTA transit system, and Construction of Interstate 66 through Arlington, Virginia.In England and Wales the Environment Agency (EA),5 formed in 1996 is a public body for protecting and improving the environment and enforces the regulations listed on the