Environmental Issues Social Studies 11 Mr. Liebert
Influence and Impact of Industrial Development on the Environment • The Industrial Revolution marked a major turning point in Earth’s ecology and humans’ relationship with their environment. • The Industrial Revolution dramatically changed every aspect of human life and lifestyles … from human development, health and life longevity, to social improvements … • The extent of the impact of human population and industry on natural resources, public health, energy usage and sanitation would only be realized in the 1960’s
Urbanization • Along with industrialization came the growth of urban centers and cities • People moved from rural existence to search for better opportunities in the growing cities and industrial factories • The impact of this industrial and population growth came at a tremendous cost to the environment and the natural resources • Natural resources were being consumed at a staggering rate to facilitate the growth of cities and industry-- eventually some of these resources became threatened and even exhausted!!
Increasing Population and Demand for Water • Without water our planet would be a barren wasteland. • There are three main ways in which people use water - municipal (drinking water and sewage treatment), industrial and agricultural (mostly irrigation) • Farming and agriculture accounts for the largest part-- about 65% of global fresh water supply was used in agriculture in 1990!! • The fresh water supply is not evenly distributed throughout the world • In many countries, the amount of water available to each person is falling, as populations rise.
Fresh Water Supply • Although water covers 75 percent of the world's surface, 97.5 percent of the earth's water is salt water; of the remaining 2.5 percent, most is locked away as groundwater or in glaciers. • Water is a finite resource: there are some 1 400 million cubic kilometres on earth and circulating through the hydrological cycle-- nearly all of this is salt water and most of the rest is frozen or under ground. • Only one-hundredth of 1 percent of the world's water is readily available for human use.
Water Contamination • Water is contaminated in a number of ways: • Garbage and litter • Sewage and waste water • Industrial waste • Radioactive waste • Marine dumping and pollution • Air pollution which causes Acid rain • Global warming • Eutrophication where water becomes oxygen starved by excess plantlife due to leaching of agricultural fertilizers
Water: A Finite Resource • There are four main factors that effect our water supply: population growth, urbanization, high levels of consumption, and climate change • Population growth: in the last century, world population has tripled. Water use has been growing at more than twice the rate of population increase in the last century, and, although there is no global water scarcity as such, an increasing number of regions are chronically short of water. • Increased urbanization will focus on the demand for water among an ever more concentrated population. • High level of consumption: as the world becomes more developed, the amount of domestic water that each person uses is expected to rise significantly. • Climate change will shrink the resources of freshwater.
Groundwater • Groundwater is held in sediments and rocks below Earth's surface. • In a natural groundwater system, water that has infiltrated the ground seeps slowly through the pores and fractures in rocks and sediments. • Some rock/sediment types store water much better than others (i.e. water can more easily be extracted). • A unit of rock or sediment that allows water to move through the pore spaces is called an aquifer
Deforestation • Deforestation is the large-scale removal of trees by any method. • From slash and burn deforestation to land clearing and more, deforestation is directly responsible for soil erosion and hinders efforts to reduce global warming. • By removing vast regions of forest, humans have reduced the planet’s ability to absorb carbon dioxide (CO₂) as well as produce oxygen (O₂) • Deforestation also displaces and endangers wildlife and threatens biodiversity
Desertification • Desertification is the degradation of formerly productive land • Desertification may intensify a general climatic trend toward greater aridity (dryness), or it may initiate a change in local climate. • Desertification became well known in the 1930's, when parts of the Great Plains in the United States and Canada turned into the "Dust Bowl" as a result of drought and poor practices in farming • Desertification occurs when the nutrients in the soil become exhausted to the point where the soil can no longer sustain vegetation • Desertification is further advanced by humans using poor agricultural methods such as slash and burn farming and overgrazing of livestock
Global Warming • There is a multitude of evidence to support the reality of global warming • Glaciers are melting, sea levels are rising, cloud forests are drying, and wildlife is scrambling to keep pace. • Humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. • These gases are called greenhouse gases because of their ability to insulate and trap heat in our atmosphere
The Greenhouse Effect • The greenhouse effect is the warming that occurs when certain gases (CO₂, CFC’s, methane, etc.) in Earth's atmosphere trap heat. • These gases let in light but keep heat from escaping, similar to the glass walls of a greenhouse. • First, sunlight shines onto the Earth's surface, where it is absorbed and then radiates back into the atmosphere as heat. • In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. • The more greenhouse gases are in the atmosphere, the more heat gets trapped.
Ozone Depletion • What is Ozone? Ozone is an irritating, corrosive, colorless gas • The ozone layer refers to the ozone within stratosphere, where over 90% of the earth's ozone resides. • Without the ozone layer, the Earth would be ravaged by solar radiation and life , as we know it, would cease to exist • The ozone layer absorbs 97-99% of the sun's high frequency ultraviolet light , light which is potentially damaging to life on earth. • For every 1% decrease in the earths ozone shield is projected to increases the amount of UV light exposure to the lower atmosphere by 2%. • In recent years, the ozone layer has been significantly reduced in areas and has formed “holes” in this vital layer that have appeared above the polar regions
Responses to Ozone Depletion • When scientists discovered what was happening to the ozone layer, they figured out what was responsible for destroying the ozone-- CFC gases • CFC’s (chlorofluorocarbons) are man made gases that are used in aerosol cans as propellants as well as in refrigeration and air conditioning units • CFC gases breakdown ozone gas and threaten the protection provided by the ozone layer • The global community responded to this threat by signing the Montreal Protocol in 1987 where all the industrial nations agreed to dramatically reduce their use of these gases
Acid Rain • Acid Rain is caused by the burning of fossil fuels and exhaust fumes produced by transportation vehicles (cars, boats, planes, trains), oil refineries, industrial factories, and smelter plants • The two most common forms of acid rain are: sulphur dioxide (SO) and nitrogen oxide (NO) • Acid rain occurs when the exhaust pollution enters the atmosphere and reacts creating rain that is acidic in nature • Acid rain has a dramatic impact upon the vegetation, the soil, and the water of a threatened region • Acid rain “knows no borders” and can be transported by winds in the atmosphere carrying pollution thousands of miles from the source
Impact of Acid Rain • Acid rain has a dramatic impact upon the environment • Acid rain kills plants and animals as well as their habitat by turning soils and groundwater acidic • Acid rain has had a dramatic impact upon coniferous trees and has destroyed vast regions of forest