6.1 A Changing Landscape

Impact of Humans on the Environment Caused extinction of species through hunting, fishing, agriculture, industry, and urban development. Growing population = greater demands on environment. Affected quality and quantity of land, air, water resources. Pollution = pollutants

Population Growth lead to…. Pollution (air/water) Deforestation Ozone depletion (CFCs) Burning of fossil fuels (Increased levels of CO2  global warming) Industrialization (Acid Rain) Usage of pesticides & herbicides  biomagnification

Impact of Humans on the Environment Air pollution = smog, acid rain, smoke, dust, gasses, fog, carbon dioxide. Water pollution = sewers, industry, farms, homes, chemical waste, fertilizer, dirty dish water. Land pollution = landfills, dumpsites, runoff, negligence, urban wastes.

Deforestation Deforestation leads to: Loss of habitat Loss of biodiversity Loss of oxygen producers and CO2 eliminators

How is Acid Rain formed? Burning of fossil fuels releases nitrates and sulfates into the air. Nitrates and sulfates mix with water vapor on air and form nitric acid and sulfuric acid (acid rain). Acid rain causes damage to plants, changes pH in soil and water systems (acidification), and chemically erodes statues, bridges and buildings.

Acidification of lakes Acidification leads to: Effects on aquatic life Reduction of nutrients Loss of oxygen producers and CO2 eliminators

Herbicides and Pesticides We spray herbicides and pesticides without knowing the possible long term consequences. (Examples PCB & DDT)

PCB &DDT Can build up in the environment causing Biological Magnification: concentration of toxic substances increasing within each of the food chains levels. Chemicals accumulate in the top predators leading to lethal effects.

Examples:

The Taj Mahal of India has suffered at the hands of acid rain as have many famous other buildings and statues around the world. What type of erosion has been caused by acid rain? Chemical erosion Wind erosion Water erosion Glacial erosion

Of the following situations, which is an affect of acid rain on the Earth’s biosphere? cause the rivers to flood, destroying many organisms’ habitat. Acid rain tends to fall only in Arctic regions Acid rain pollutes useable water in lakes, rivers, and oceans and could potentially poison the plants or animals consuming it. The organisms in Earth’s biosphere are rarely affected by acid rain and can filter out the unwanted chemicals.

Conservation Efforts: Conserve energy resources Protect and conserve material resources Control pollution (recapture wastes, carpooling, solid waste neutralization) Wildlife conservation protect animals from habitat loss, over-hunting, pollution Reduce reuse, recycle programs Sanitation and waste disposal programs.

Sustainability When the number of individuals and the flow of resources are maintained.

Sustainable Development What is the relationship between resource use and sustainable development?

Sustainable Development What is the relationship between resource use and sustainable development? Sustainable development provides for human needs while preserving the ecosystems that produce natural resources.

Sustainable Development Goods are things that can be bought and sold, that have value in terms of dollars and cents. Services are processes or actions that produce goods. Ecosystem goods and services are the goods and services produced by ecosystems that benefit the human economy.

Ecosystem Goods and Services Healthy ecosystems provide many goods and services naturally and largely free of charge, like breathable air and drinkable water.

Ecosystem Goods and Services But, if the environment can’t provide these goods and services, society must spend money to produce them. In many places, for example, drinkable water is provided naturally by streams, rivers, and lakes, and filtered by wetlands.

Ecosystem Goods and Services If the water sources or wetlands are polluted or damaged, water quality may fall. Cities and towns must then pay for mechanical or chemical treatment to provide safe drinking water.

Renewable and Nonrenewable Resources Ecosystem goods and services are classified as either renewable or nonrenewable. A renewable resource can be produced or replaced by natural process in a reasonable amount of time. Wind is a renewable resource.

Renewable and Nonrenewable Resources Some resources are nonrenewable resources because natural processes cannot replenish them within a reasonable amount of time. Fossil fuels like coal, oil, and natural gas are nonrenewable resources formed from buried organic materials over millions of years. Nonrenewable resources are not sustainable because they will become increasingly rare and costly, and someday wo;; be effectively exhausted.

Sustainable Resource Use Using natural resources in a way that does not cause long-term environmental harm is called sustainable development. Sustainable development should cause no long-term harm to the soil, water, and climate on which it depends. It should consume as little energy and material as possible. Sustainable development must be flexible enough to survive environmental stresses like droughts, floods, and heat waves or cold snaps. Sustainable development must also take into account human economic systems as well as ecosystem goods and services.

Examples:

One way that humans could have a positive impact on local environments is to: A. generate waste products as a result of technological advances B. use resources that are renewable C. increase planting large areas of one crop D. increase the use of pesticides

Answer: B

One way humans can promote the survival of organisms in an ecosystem is to: A.decrease diversity in plant habitats B. introduce new consumers to control autotrophs C. release extra CO2 into the atmosphere to help autotrophs D. learn about the interactions of population

Answer: D

New fuels are being produced by converting corn and grasses into compounds containing alcohols that can be broken down for energy in various engines. The purpose of this research is to A. reduce the use of nonrenewable resources. B. increase the rate of air pollution. C. reduce the rate of homeostasis in organisms. D. cause a loss of biodiversity in the rain forests.

Answer: A

Salt water is an abundant resource but unusable for irrigation and drinking. As demands on freshwater sources increase, the use of desalination processes to remove salt from ocean water is increasing. A concern of desalinating water is the large amounts of recovered salts that are returned to the ocean. Which of the following describes the most likely impact of desalination on the surrounding ocean environment?  A. Methane gas would pollute the ocean environment as shoreline organisms begin to die and decay. B. Alteration in ocean salt levels would cause loss of species and unbalanced populations in marine food webs. C. Nonrenewable resources in the ocean environment would become depleted and upset the ecosystem's balance. D. Increased levels of salts and minerals in the ocean would result in overpopulation of marine bivalves due to strengthened shells.

Answer: B. Alteration in ocean salt levels would cause loss of species and unbalanced populations in marine food webs. Any change in abiotic factors (such as salinity) will have effects on the organisms in an ecosystem.