Energy Production

The limited supply of fossil fuels,coupled with their contribution to global warming,air pollution,and acid rain,makes it clear that alternative forms of energy will needed to fuel industrial production and transportation.A number of energy alternatives are available,but many of these options are unlikely to replace fossil fuels in the fore see able future because they cost more,produce less energy than fossil fuels,or pose safety risks.

Air Pollution

A significant portion of industry and transportation burns fossil fuels,such as gasoline.When these fuels burn,chemicals and particulate matter are released into the atmosphere.Although a vast number of substances contribute to air pollution,the most air pollutants contain carbon,sulfur,and nitrogen.These chemicals interact with one another and with ultraviolet radiation in sunlight in dangerous ways.Smog,usually found in urban areas with large numbers of automobiles,forms when nitrogen oxides react with hydro carbons in the air to produce al dehydes and ketones.Smog can cause serious health problems.

Environmental Racism

Studies have shown that not all individuals are equally exposed to pollution.Environmental racism takes international forms as well.Americans corporations often continue to produce dangerous,U.S.-banned chemicals and ship them to developing countries.Additionally the developed world has shipped large amounts of toxic waste to developing countries for less than safe disposal.For instance,experts estimates that 5o to 80 percent of electronic waste produced in the United States,including computer parts,is shipped to waste sites in developing countries,such as China and India.A t a waste site in Giugu,China,laborers with no protective clothing regularly burn plastics and circuit boards from old computers.They pour acid on electronic parts to extract silver and gold,and they smash cathode-ray tubes from computer monitors to remove lead

Chemicals Risks

A number of toxic substances that humans encounter regularly may pose serious health risks.Pesticide residues on vegetable crops,mercury in fish,and many industrially produced chemicals may cause cancer,birth defects,genetic mutations,or death.Many chemicals have been found to mimic estrogen,the hormone that controls the development of the female reproductive system in a large number of animal species.Pre liminary results indicate that these chemicals,in trace amounts,may disrupt development and lead to a host of serious problems in both males and females,including infertility,increased mortality of offspring,and behavioral changes such as increased aggression.

Water Pollution

Estimates suggest that nearly 1.5 billion people worldwide lack safe drinking water and that at least 5 millions deaths per year can be contributed to water- borne diseases.Water pollution may come from point sources or non point sources.Point sources discharge pollutants from specific locations,such as factories,sewage treatment plants,and oil tankers.The technology exists to monitor and regulate point sources of pollution,although in some areas this occurs only sporadically.Pollution from non point sources occurs when rain fall and snow melt moves over and through the ground.As the run-off moves,it picks and carries away pollutants,such as pesticides and fertilizers,depositing the pollutants into lakes,rivers,wetlands,coastal waters,and even underground sources of drinking water.Pollution arising from non point sources accounts for a majority of the contaminants in streams and lakes.

Habitat Destruction And Species Extinction

Planet and animal species are dying out at an unprecedented rate.Estimates range that from 4,000 to as many 5,000 species per year become extinct.The leading cause of extinction is habitat destruction,particularly of the world's richest ecosystem tropical rainforest's and coral reefs.If the world's rain forests continue to be cut down at the current rate,they may be completely disappear by the year 2030.In addition,if the world's population continues to grow at its present rate and puts even more pressure on this habitats,they might well be destroyed sooner.

Depletion Of Ozone Layer

The ozone layer,a thin band in the stratosphere serves to shield earth from the sun's harmful ultraviolet rays.Chlorofluorocarbons chemicals used in refrigerator, air conditioning system etc destroy the ozone layer.CFC release chlorine into the atmosphere;chlorine,in turn,breaks down ozone molecules.Because chlorine is not affected by it's interaction with ozone,each chlorine molecule has the ability to destroy a large amount of ozone for an extended period of time.The consequences of continued depletion of ozone layer would be dramatic.Increased ultraviolet radiation would lead to a growing number of skin cancer and cataracts and also reduce the ability of immune systems to respond to infection.

Global Warming

Certain gases in the earth's atmosphere permit the sun's radiation to heat earth. At the same time, these gases retard the escape into space of the infrared energy radiated back out by Earth. This process is referred to as the greenhouse effect.These gases,primarily carbon dioxide,methane,nitrous oxide,and water vapour,insulate earth's surface,helping to maintain warm temperatures,without these gases,earth would be a frozen planet with an average temperature of about -18degree Celsius instead of comfortably 15degree Celsius.If the concentration of these gases rises,they trap more heat within the atmosphere,causing worldwide temperature to rise.

Population Growth

Human population growth is at the root of virtually all of the world's environmental problems.Although the growth rate of the world's population has slowed slightly since the 1990's ,the world's population increases by about 77 million human beings each year. As the number of people increases ,crowding generates pollution,destroys more habitats,and uses up additional natural resources.