CHAPTER 6: HUMANS IN THE BIOSPHERE

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1 CHAPTER 6: HUMANS IN THE BIOSPHERE

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3 Bell Ringer How do you impact your environment by every day actions? Write a brief paragraph explaining your impact on the world, why it is an impact, and whether it is positive or negative.

4 What happens when a growing human population doesn t adequately manage natural resources that are both vital and limited?

5 The Effect of Human Activity We affect the environment when we obtain Food Eliminate waste products Build places to live Effects may not be very large here, but in islands like Hawaii with a small surface area, they are huge!

6 The Effect of Human Activity Humans affect regional and global environments through agriculture, development, and industry Huge impact on the quality of Earth s natural resources (including soil, water, and the atmosphere).

7 6.1: A CHANGING LANDSCAPE HUMANS IN THE BIOSPHERE IN 1778, EUROPEANS ARRIVED ON THE ISLAND CHAIN OF HAWAII. THEY CHANGED THE ISLANDS BY INTRODUCING RANCHING, PREDATORS, AND DISEASE. LARGE AREAS HAVE BEEN PAVED FOR HOUSING SCHOOLS AND INDUSTRY; NATIVE HAWAIIAN SPECIES ARE GONE

8 EARTH AS AN ISLAND All organisms on Earth share a limited resource base and depend on it for their long-term survival. HUMAN POPULATION IS INCREASING; OUR PLANET IS NOT To protect these resources, we need to understand how humans interact with the biosphere.

9 HUMAN ACTIVITIES INDUSTRY AND TECHNOLOGY GIVE HUMANS A STRONG ADVANTAGE IN COMPETING FOR FOOD, ENERGY, AND SPACE HUMANS ARE THE MOST IMPORTANT SOURCE OF ENVIRONMENTAL CHANGE ON THE PLANET What types of human activities can affect the biosphere?

10 SOME ACTIVITIES THAT HAVE TRANSFORMED THE BIOSPHERE HUNTING AND GATHERING AGRICULTURE INDUSTRY URBAN DEVELOPMENT

11 HUNTING AND GATHERING THIS USED TO BE THE PRIMARY MEANS OF SURVIVAL PEOPLE LIVED IN SMALL GROUPS HUNTING AND GATHERING CAUSED ONE OF THE MAJOR MASS EXTINCTIONS OF LARGE ANIMALS (WOOLY MAMMOTHS, GIANT SLOTHS, AND SABERTOOTH CATS) PEOPLE STILL FOLLOW THIS WAY OF LIFE AND SUPPLEMENT THEIR DIET WITH THE MEAT OF WILD ANIMALS: SUBSISTENCE HUNTING SUBSISTENCE HUNTING ALLOWS THE USE OF GUNS, SNOWMOBILES, TOOLS, ETC. What are some of the disadvantages of relying on hunting and gathering to obtain all the food you need?

12 AGRICULTURE (FARMING) THE SPREAD OF AGRICULTURE WAS IMPORTANT BECAUSE IT PROVIDED PEOPLE WITH A DEPENDABLE SUPPLY OF FOOD HUMANS GATHERED IN LARGER SETTLEMENTS (TOWNS AND CITIES) AND DEVELOPED GOVERNMENT AND LAWS.

13 Agriculture Modern agricultural practices have enabled farmers to double world food production over the last 50 years Much more food and it can be stored for long periods Monoculture: the practice of clearing large areas of land to plant a single highly productive crop year after year Ex: Soybeans

14 Agriculture Providing food for 7 billion people, though, puts a strain on natural resources like water and fertilized land This is why we invented fertilizers and farm machinery (which also takes a lot of fossil fuel)

15 DOMESTICATION OF ANIMALS (SHEEP, GOATS, COWS, PIGS, HORSES, DOGS) SUPPLIED HUMANS WITH MILK, WOOL, ETC. OVERGRAZING CHANGED GRASSLAND ECOSYSTEMS, ERODED SOIL, AND PUT LARGE DEMANDS ON WATER SUPPLIES TRADITIONAL AGRICULTURE ( ) ALLOWED FOR THE EXCHANGE OF FOODS AROUND THE WORLD TO BEGIN

16 1800 S: IRRIGATION, NEW CROP VARIETIES, AND FARM MACHINES HELPED FARMERS INCREASE THEIR YIELDS TREMENDOUSLY GREEN REVOLUTION: GOVERNMENTS AND SCIENTISTS INTRODUCED NEW, INTENSIVE FARMING PRACTICES THAT GREATLY INCREASED THE YIELDS OF RICE, WHEAT, ETC.

17 Copyright Pearson Prentice Hall Agriculture The Green Revolution The green revolution was an effort in the midtwentieth century to increase global food production through modern plant breeding and agricultural techniques. Over the last 50 years, the green revolution has helped world food production double.

18 STRATEGIES OF THE GREEN REVOLUTION DEVELOPMENT OF NEW, HIGHLY PRODUCTIVE VARIETIES OF MAJOR FOOD CROPS=MIRACLE STRAINS MONOCULTURE: LARGE FIELDS ARE CLEARED, PLOWED AND PLANTED WITH A SINGLE CROP YEAR AFTER YEAR FARMERS RELY ON IRRIGATION, CHEMICAL FERTILIZERS, AND PESTICIDES THE BENEFIT TO HUMANS FROM THE GREEN REVOLUTION IS NEW FARMING PRACTICES INCREASED FOOD PRODUCTION AND PREVENTED FOOD SHORTAGES

19 PROBLEMS WITH THE GREEN REVOLUTION Challenges for the Future While increasing world food supplies, modern agriculture has created ecological challenges. For example: INTENSIVE FARMING CAN DEPLETE ENERGY AND WATER SUPPLIES MONOCULTURE ALLOWS PESTS TO REPRODUCE QUICKLY PESTICIDES CARRY HARMFUL CHEMICALS FERTILIZERS CAN INTERFERE WITH FOOD WEBS AND BIOGEOCHEMICAL CYCLES

20 INDUSTRIAL GROWTH AND URBAN DEVELOPMENT HUMAN SOCIETY WAS TRANSFORMED BY THE INDUSTRIAL REVOLUTION MOST ENERGY NEEDED TO PRODUCE POWER CAME FROM FOSSIL FUELS (COAL, OIL, NATURAL GAS) URBAN CENTERS BECAME CROWDED AND PEOPLE MOVED FROM CITIES TO SUBURBS INDUSTRIAL PROCESSES POLLUTE AIR, WATER, AND SOIL

21 Industrial Growth We have a lot of conveniences now that allow us comfy homes, clothes and electronic devices but these all require energy to produce and power! We get most of this energy from fossil fuels (coal, oil and natural gas) Suburban growth consumes farmland and stresses native plants and animals.

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23 Sustainable Development Most ecosystems provide us with goods and services like water and air If it can t, then we must spend money in order to produce them If the water isn t being cleaned by the natural rivers and wetlands, we have to pay for chemicals and mechanics to make it safe to drink

24 Sustainable Development Renewable resource: can be produced or replaced by a healthy ecosystem Ex: Water, wind, organisms Nonrenewable resource: can t replenish them within a reasonable amount of time Ex: Fossil fuels like coal, oil and natural gas

25 Using Resources Wisely 6.2 How do we obtain what we need from our local and global environments without destroying those environments? Not farming is not an option, we all need to eat and depend on things like wheat in many ways!

26 6-2 Renewable and Nonrenewable Resources

27 RENEWABLE AND NONRENEWABLE RESOURCES A RESOURCE IS SOMETHING THAT CAN BE DRAWN UPON TO TAKE CARE OF A NEED A COMMON RESOURCE IS AN ENVIRONMENTAL RESOURCE OWNED BY MANY PEOPLE IN COMMON TRAGEDY OF THE COMMONS : ANY RESOURCE THAT IS OPEN TO EVERYONE (AIR, OCEANS) WILL EVENTUALLY BE DESTROYED BECAUSE EVERYONE CAN USE IT, BUT NO ONE IS RESPONSIBLE FOR PRESERVING IT

28 Copyright Pearson Prentice Hall Classifying Resources How are environmental resources classified? +Environmental goods and services may be classified as either renewable or nonrenewable.

29 Copyright Pearson Prentice Hall Classifying Resources Renewable resources can regenerate if they are alive, or can be replenished by biochemical cycles if they are nonliving. Can be limited though A tree is an example of a renewable resource because a new tree can be planted in place of an old tree that dies or is cut down.

30 Copyright Pearson Prentice Hall Classifying Resources A nonrenewable resource is one that cannot be replenished by natural processes. Fossil fuels such as coal, oil, and natural gas are nonrenewable resources. Once these fuels are depleted, they are gone forever.

31 Copyright Pearson Prentice Hall Sustainable Development What effects do human activities have on natural resources? +Human activities can affect the quality and supply of renewable resources such as land, forests, fisheries, air, and fresh water.

32 Sustainable development is a way of using natural resources without depleting them, and of providing for human needs without causing long-term environmental harm. ***UNLESS SUSTAINABLE STRATEGIES ARE USED, HUMAN ACTIVITIES CAN DAMAGE/DEPLETE RESOURCES

33 Sustainable Development Sustainable development: using resources in an environmentally conscious and friendly way. Provides for human needs while preserving the ecosystem that produces those natural resources

34 Sustainable Development It should: Cause no long-term harm to the ecosystem Consume as little energy and material as possible Should be able to withstand environmental stresses (droughts, floods, heat waves, cold snaps) Help people improve their situation

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36 Copyright Pearson Prentice Hall Land Resources Land Resources Land provides space for human communities and raw materials for industry. Land also includes the soils in which crops are grown. If managed properly, soil is a renewable resource.

37 LAND RESOURCES IF MANAGED PROPERLY, SOIL IS RENEWABLE. IF NOT, IT WILL BE PERMANENTLY DAMAGED. FERTILE SOIL: BEST FOR FOOD CROPS TO GROW; CONTAINS A MIXTURE OF HUMUS, SAND, CLAY AND ROCK HUMUS IS MOSTLY TOPSOIL THAT ABSORBS AND RETAINS NUTRIENTS ( material from decayed organisms) PLOWING: REMOVES ROOTS THAT HOLD SOIL IN PLACE SOIL EROSION=THE WEARING AWAY OF SURFACE SOIL BY WATER AND WIND

38 Soil Resources Healthy soil supports both agriculture and forestry Your cereal this morning and the paper of your textbook both depend on soil

39 Soil Resources Topsoil: the mineral and nutrient rich portion of soil Rich in organic matter and nutrients Allows water to drain Produced by long-term interactions between plants Can be renewable if managed correctly

40 Soil Erosion Soil erosion: the removal of soil by water or wind Soil erosion is common when land is plowed and left barren all organic materials are carried away Desertification: when dry climates, farming, and overgrazing cause a productive area to turn into a desert. Caused by farming, overgrazing and drought Happened to the Great Plains in the Dust Bowl

41 Soil Resources If not managed correctly, topsoil can be depleted and we lose our farming grounds The great Dust Bowl in the 1930 s long drought and bad farming led to a loss of many jobs and fertile land

42 Forest Resources Forest Resources Earth s forests are an important resource for the products they provide and for the ecological functions they perform.

43 Forest Resources Forest Resources: provide wood for products and fuel. remove carbon dioxide and produce oxygen. store nutrients. provide habitats and food for organisms. moderate climate. limit soil erosion. protect freshwater supplies.

44 Forest Resources Some areas can re-grow their forests but remember succession (which kind??) takes years!! Other areas, like the rainforest, can t re-grow. Nonrenewable! Whether a forest can be considered a renewable resource depends partly on the type of forest. Temperate forests of the Northeast are renewable because they have been logged and have grown back naturally. Old-growth forests, such as those in Alaska and the Pacific Northwest, are nonrenewable because it takes centuries to produce them.

45 Copyright Pearson Prentice Hall Forest Resources +Deforestation Loss of forests, or deforestation, has several effects: Erosion can wash away nutrients in the topsoil. Grazing or plowing can permanently change local soils and microclimates, which prevents the regrowth of trees. Deforestation: the loss of forests Also has an effect on soil quality because forests hold the soil in place, protect the quality of the water, absorb carbon dioxide and help the climate.

46 Soil Erosion Deforestation can make matters worse if you allow overgrazing and farming in rainforests The topsoil layer in rainforests is very thin, so the organic matter is used up quickly (within a few years)

47 Copyright Pearson Prentice Hall Forest Resources +Forest Management Mature trees can be harvested selectively to promote the growth of younger trees and preserve the forest ecosystem. Tree geneticists are breeding new, fastergrowing trees that produce high-quality wood.

48 Soil Use and Sustainability It is possible to minimize soil erosion through careful management of both agriculture and forestry Leave the stems! Don t take everything off Crop rotation! Change the type of crop and how often Terrace the land create steps to help hold the soil Selectively harvest trees! Out with the old, in with the new!

49 Sustainable development A variety of sustainable-development practices can prevent problems such as soil erosion and desertification. +Sustainable-development practices include: contour plowing fields are plowed across the slope of the land to reduce erosion leaving stems and roots of the previous year's crop in place to help hold the soil planting a field with rye rather than leaving it unprotected from erosion

50 Copyright Pearson Prentice Hall Freshwater Resources Freshwater Resources Americans use billions of liters of fresh water daily for everything from drinking and washing to watering crops and making steel. Although water is a renewable resource, the total supply of fresh water is limited and is threatened by pollution.

51 Freshwater Resources Remember. Only 3% of Earth s water is freshwater and most of it is frozen in the ice caps! We must protect the ecosystems that collect and purify freshwater

52 WATER RESOURCES OVERALL, WATER IS A RENEWABLE RESOURCE. FRESHWATER IS LIMITED AS A RESOURCE. POLLUTION THREATENS WATER SUPPLIES: + OIL SPILLS + IMPROPER DISPOSAL OF CHEMICALS LEADS TO THEIR SEEPAGE INTO STREAMS AND RIVERS + WASTE DISCARDED ON LAND SEEPS INTO SOIL AND ENTERS GROUNDWATER SUPPLIES + DOMESTIC SEWAGE CONTAINS NITROGEN AND PHOSPHORUS COMPOUNDS THAT ENCOURAGES GROWTH OF ALGAE AND BACTERIA IN AQUATIC HABITATS + SEWAGE CONTAINING MICROORGANISMS ALSO SPREADS DISEASE AMONG HUMANS AND ANIMALS

53 Freshwater Resources Pollutant: any harmful material that can enter the biosphere Point source pollution: when pollution enters water from one source Ex: From a factory or an oil spill

54 Freshwater Resources Nonpoint sources: when pollutants enter water supplies from many smaller sources Ex: the grease and oil washed off streets by rain

55 Freshwater Resources The primary sources of water pollution are: Industrial and agricultural chemicals Residential sewage

56 Residential Sewage Where does the waste in your toilet go when it flushes? Contaminates water (both fresh and salt) with microorganisms, and depletes it of oxygen

57 Copyright Pearson Prentice Hall Freshwater Resources +Sustainable Use of Water One way to ensure the sustainable use of water is to protect the natural systems involved in the water cycle that help purify water. These include: wetlands forests other vegetation Also, by conserving water in: home industry agriculture

58 Water Quality and Sustainability Watershed conservation: clean all areas, including the areas that drop water off, to prevent pollution Sewage treatments to eliminate bacteria and disease Use integrated pest management (IPM) natural predators to the pests instead of pesticides Drip irrigation: delivers water drop by drop directly to the roots of the plants that need it

59 FISHERY RESOURCES Fish and other animals that live in the water are VALUABLE FOR FOOD Overfishing, or harvesting fish faster than they can be replaced by reproduction, has greatly reduced the amount of fish in parts of the world s oceans. Until recently, fisheries seemed to be a renewable resource, but overfishing has limited that resource.

60 Copyright Pearson Prentice Hall Fishery Resources +Sustainable Development The U.S. National Marine Fisheries Service has issued guidelines that specify how many fish, and of what size, can be caught in various parts of the oceans. The regulations have helped fish populations recover.

61 Fishery Resources This graph shows how the cod population has changed in Georges Bank, a fishery off the New England coast. The fish population began to rise after regulations restricted commercial fishing.

62 Copyright Pearson Prentice Hall Fishery Resources This graph shows how the haddock population has changed in Georges Bank, a fishery off the New England coast. The fish population began to rise after regulations restricted commercial fishing.

63 SUSTAINABLE USE OF FISHERIES LIMIT THE CATCH OF FISH POPULATIONS: THE PROBLEM IS THAT OPEN OCEAN WATERS ARE OUTSIDE THE CONTROL OF ANY ONE SINGLE COUNTRY. AN EXAMPLE OF A COMMON RESOURCE THAT EVERYONE WANTS BUT NO ONE HAS INCENTIVE TO PROPERLY MANAGE AQUACULTURE: FARMING OF AQUATIC ORGANISMS + GOOD BECAUSE IT PRODUCES ANIMAL PROTEIN + IF IT ISNT MANAGED, THIS POLLUTES WATER WITH FISH WASTES

64 Atmospheric Resources We need oxygen to breathe! But our pollution is breaking down the ozone layer, which provides us with protection from UV radiation

65 Atmospheric Resources Common forms of air pollution include Smog Acid rain Greenhouse gases Particulates Cause respiratory illness (asthma), change climate patterns and increase skin disease PARTICULATES: MICROSCOPIC PARTICLES OF ASH AND DUST THAT CAUSE HEALTH PROBLEMS (MOST INDUSTRIES USE TECHNOLOGY TO CONTROL EMISSIONS)

66 AIR RESOURCES SMOG: MIXTURE OF CHEMICALS THAT OCCURS AS A GRAY-BROWN HAZE IN THE ATMOSPHERE; IT IS A COMBINATION OF SMOKE AND FOG, MOSTLY DUE TO AUTOMOBILE EXHAUSTS AND INDUSTRY EMISSIONS Considered a pollutant because it threatens peoples health

67 Copyright Pearson Prentice Hall Air Resources A pollutant is a harmful material that can enter the biosphere through the land, air, or water. The burning of fossil fuels can release pollutants that cause smog and other problems in the atmosphere. Strict automobile emissions standards and clean-air regulations have improved air quality in many cities, but air pollution is still a problem.

68 Air Resources COMBUSTION: RELEASES ACIDIC GASES CONTAINING NITROGEN AND SULFUR COMPOUNDS INTO THE ATMOSPHERE. WHEN THEY COMBINE WITH WATER VAPOR, NITRIC AND SULFURIC ACIDS ARE FORMED AND FALL TO EARTH S SURFACE AS ACID RAIN. Acid rain kills plants by damaging their leaves and changing the chemistry of soils and standing-water ecosystems. Acid rain may dissolve and releases toxic elements, such as mercury, from the soil, freeing the elements to enter other portions of the biosphere.

69 Copyright Pearson Prentice Hall Air Resources Formation of Acid Rain Acid rain results from the chemical transformation of nitrogen and sulfur products that come from human activities. Emissions to Atmosphere Nitrogen oxides Sulfur dioxide Chemical Transformation Nitric acid Sulfuric acid Dry Fallout Particulates Gases Condensation Precipitation Acid rain, fog, snow, and mist Industry Transportation Ore smelting Power generation

70 6-3: BIODIVERSITY VARIETY IS ALSO KNOWN AS DIVERSITY. BIODIVERSITY: THE SUM TOTAL OF THE GENETICALLY BASED VARIETY OF ALL ORGANISMS IN THE BIOSPHERE ECOSYSTEM DIVERSITY: VARIETY OF HABITATS, COMMUNITIES, AND ECOLOGICAL PROCESSES IN THE LIVING WORLD SPECIES DIVERSITY: NUMBER OF DIFFERENT SPECIES IN THE BIOSPHERE GENETIC DIVERSITY: SUM TOTAL OF ALL DIFFERENT FORMS OF GENETIC INFORMATION CARRIED BY ALL ORGANISMS LIVING ON EARTH

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72 Why is biodiversity importnant? BIODIVERSITY IS ONE OF EARTH S GREATEST NATURAL RESOURCES SPECIES HAVE PROVIDED US WITH: + FOODS + MEDICINES + ANTICANCER DRUGS + PAINKILLERS + ANTIBIOTICS + HEART DRUGS + ANTIDEPRESSANTS

73 THREATS TO BIODIVERSITY What are current threats to biodiversity? HUMAN ACTIVITY IS THE NUMBER ONE THREAT! WE ALTER HABITATS, HUNT SPECIES TO EXTINCTION, INTRODUCE TOXIC COMPOUNDS INTO FOOD WEBS, AND INTRODUCE FOREIGN SPECIES TO A NEW ENVIRONMENT

74 EXTINCTION: OCCURS WHEN A SPECIES DISAPPEARS FROM ALL OR PART OF ITS RANGE ENDANGERED SPECIES: SPECIES WHOSE POPULATION SIZE IS DECLINING AND IN DANGER OF EXTINCTION As the population of an endangered species declines, the species loses genetic diversity.

75 HABITAT ALTERATION AND FRAGMENTATION WHEN LAND IS DEVELOPED, NATURAL HABITATS ARE DESTROYED. SPECIES VANISH AS A RESULT. HABITAT FRAGMENTATION: LAND DEVELOPMENT SPLITS ECOSYSTEMS INTO PIECES; THESE PIECES BECOME BIOLOGICAL ISLANDS ANY PATCH OF HABITAT SURROUNDED BY A DIFFERENT HABITAT *THE SMALLER THE ISLAND, FEWER SPECIES CAN LIVE THERE, RESULTING IN SMALLER POPULATIONS*

76 Copyright Pearson Prentice Hall Demand for Wildlife Products Demand for Wildlife Products Throughout history, humans have pushed some animal species to extinction by hunting them for food or other products. Today, in the U.S., endangered species are protected from hunting.

77 DEMAND FOR WILDLIFE PRODUCTS HUNTING HAS CAUSED EXTINCTION FOR MANY SPECIES TODAY, ENDANGERED SPECIES ARE PROTECTED FROM HUNTING IN THE U.S. AFRICA, SOUTH AMERICA, AND ASIA STILL ALLOW HUNTING OF ANIMALS FOR FOOD, FUR, HIDES, ETC. The Convention on International Trade in Endangered Species, CITES, bans international trade in products derived from endangered species. CITES=CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES; IT BANS TRADE IN PRODUCTS DERIVED FROM AN AGREED UPON LIST OF ENDANGERED SPECIES

78 POLLUTION: SERIOUS PROBLEM THREATENING BIODIVERSITY ONE OF THE MOST SERIOUS OCCURS WHEN TOXIC COMPOUNDS ACCUMULATE IN TISSUES OF ORGANISMS (EX. DDT) 1. DDT WAS THOUGHT TO BE HARMLESS - REMAINS ACTIVE FOR A LONG TIME, KILLS MANY DIFFERENT INSECTS, AND WAS CHEAP 2. WHEN SPRAYED, DRAINED INTO WATER SUPPLIES

79 Industrial and Agricultural Chemicals When DDT enters food webs, it undergoes biological magnfication. In biological magnification, concentrations of a harmful substance increase in organisms at higher trophic levels in a food chain or food web. When a pollutant (like DDT or mercury) is picked up by an organism and is not broken down or eliminated from its body Concentration increases as it goes up the food chain

80 Industrial and Agricultural Chemicals The concentration of DDT was so high at one point that it threatened the existence of our national bird the Bald Eagle

81 Industrial and Agricultural Chemicals Industrial pollutants are difficult to eliminate because they stay underneath the ground, in the sand and mud Ex: PCB s these were banned in the 1970 s Ex: DDT, a pesticide and insecticide that ran off into water supply

82 TWO PROPERTIES THAT MAKES DDT HAZARDOUS 1. NON-BIODEGRADABLE: NOT BROKEN DOWN IN NATURE 2. NOT ELIMINATED FROM THE BODIES OF ORGANISMS AS THEY PICK IT UP DDT IS CONCENTRATED AND STORED IN AQUATIC PLANTS/ALGAE HERBIVORES EAT PLANTS AND GET 10 TIMES THE CONCENTRATION THE PLANTS HAD CARNIVORES EAT HERBIVORES AND DDT IS CONCENTRATED EVEN MORE=PROCESS OF BIOLOGICAL MAGNIFICATION

83 BIOLOGICAL MAGNIFICATION: CONCENTRATIONS OF A HARMFUL SUBSTANCE INCREASES IN ORGANISMS AT HIGHER TROPHIC LEVELS IN A FOOD CHAIN/WEB BY THE 1970 S, DDT WAS BANNED IN THE U.S. RACHEL CARSON WROTE A BOOK IN 1962, TITLED SILENT SPRING WHICH alerted people to the dangers of biological magnification and EXPLAINED THE RESULTS OF USING THE PESTICIDE DDT.

84 Copyright Pearson Prentice Hall Pollution Magnification of DDT Concentration

85 Copyright Pearson Prentice Hall Pollution Magnification of DDT Concentration

86 Copyright Pearson Prentice Hall Pollution Magnification of DDT Concentration

87 Copyright Pearson Prentice Hall Pollution Magnification of DDT Concentration

88 Copyright Pearson Prentice Hall Pollution Magnification of DDT Concentration

89 Copyright Pearson Prentice Hall Pollution Magnification of DDT Concentration

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93 Copyright Pearson Prentice Hall Introduced Species Introduced Species Another threat to biodiversity comes from plants and animals that humans transport around the world either accidentally or intentionally. Invasive species are introduced species that reproduce rapidly because their new habitat lacks the predators that would control their population.

94 CONSERVING BIODIVERSITY CONSERVATION: WISE MANAGEMENT OF NATURAL RESOURCES LIKE THE PRESERVATION OF HABITATS AND WILDLIFE Strategies for Conservation Many conservation efforts are aimed at managing individual species to keep them from becoming extinct. STRATEGIES FOR CONSERVATION: 1. CAPTIVE BREEDING PROGRAMS 2. FOCUS ON PROTECTING ENTIRE ECOSYSTEMS AS WELL AS SINGLE SPECIES 3. GOVERNMENT SETS ASIDE LAND, EXPANDS EXISTING AREAS AS PARKS/RESERVES 4. MARINE SANCTUARIES

95 Conserving Biodiversity What is the goal of conservation biology? +Conservation efforts focus on protecting entire ecosystems as well as single species. +Protecting an ecosystem will ensure that the natural habitats and the interactions of many different species are preserved at the same time.

96 Conserving Biodiversity Conservation Challenges Protecting resources for the future can require people to change the way they earn their living today. Conservation regulations must be informed by solid research and must try to maximize benefits while minimizing economic costs. THE NEED TO PROTECT BIODIVERSITY IS GREATEST IN COUNTRIES LEAST ABLE TO DO SO RAINFOREST DESTRUCTION IS THE GREATEST THREAT TO BIODIVERSITY ON LAND CONSERVATION BIOLOGISTS IDENTIFY HOT SPOTS WHERE SIGNIFICANT NUMBERS OF HABITATS AND SPECIES ARE IN DANGER OF EXTINCTION

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98 6-4: CHARTING A COURSE FOR THE FUTURE MANY BIOLOGISTS ARE CONCERNED ABOUT THE BIOLOGICAL EFFECTS OF TWO TYPES OF GLOBAL CHANGE: 1. THE THINNING OR DEPLETION OF THE OZONE LAYER 2. GLOBAL CLIMATE SYSTEM

99 OZONE DEPLETION (O3) OZONE LAYER IS KM ABOVE EARTH S SURFACE OZONE AT GROUND LEVEL IS A POLLUTANT OZONE LAYER ABSORBS UV RADIATION FROM SUNLIGHT BEFORE IT REACHES EARTH S SURFACE

100 EXPOSURE TO UV RADIATION CAUSES: SUNBURN CANCER DAMAGE TO EYES DECREASED RESISTANCE TO DISEASE damage plant leaf tissue and phytoplankton in the oceans *THE OZONE LAYER SERVES AS A GLOBAL SUNSCREEN BECAUSE IT SHIELDS THE BIOSPHERE FROM UV LIGHT

101 1970 S: HOLE DISCOVERED IN OZONE LAYER OVER ANTARCTICA 1995: OZONE HOLE LARGE ENOUGH TO EXPOSE PARTS OF THE US TO HIGH LEVELS OF UV CFC S: CHLOROFLOUROCARBONS: ACT AS CATALYSTS THAT ENABLE UV LIGHT TO BREAK APART OZONE MOLECULES

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103 Ozone Depletion One Solution CFCs (chlorofluorocarbons) were once widely used: as propellants in aerosol cans as coolant in refrigerators, freezers, and air conditioners in the production of plastic foams The U.S. and other nations began reducing the use of CFCs in 1987, and eventually banned them.

104 Ozone Depletion Copyright Pearson Prentice Hall

105 GLOBAL WARMING GLOBAL WARMING IS AN INCREASE IN THE AVERAGE TEMPERATURE OF THE BIOSPHERE TEMPERATURES BETWEEN 1980 AND 2000 ROSE AT A FASTER RATE THAN DURING THE PREVIOUS 100 YEARS One sign of global warming is melting of polar ice 1990 S WERE THE HOTTEST DECADE EVER RECORDED

106 Global Climate Change Biologists are concerned about global warming. This map of the Arctic is based on images taken by satellites in 1979 and Sea ice in the Arctic Ocean has receded so quickly that some scientists suggest that, within the next 50 years, the ice could disappear completely.

107 Global Climate Change Evidence of Global Warming The geological record shows that Earth s climate has changed repeatedly during its history.

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110 CAUSES OF GLOBAL WARMING 1. HUMAN ACTIVITIES HAVE ADDED CARBON DIOXIDE AND OTHER GREENHOUSE GASES SUCH AS METHANE TO THE ATMOSPHERE. 2. GLOBAL ATMOSPHERE GREENHOUSE RETAINS MORE HEAT. 3. THE BURNING OF FOSSIL FUELS ADDS CARBON DIOXIDE TO THE ATMOSPHERE, AS DOES CUTTING DOWN AND BURNING FORESTS. 4. NATURAL VARIATIONS IN CLIMATE:AVERAGE GLOBAL SURFACE TEMPERATURE WILL INCREASE BY 1-2 DEGREES CELSIUS BY 2050

111 IF GLOBAL WARMING CONTINUES AT CURRENT RATES, THE POLAR ICE CAPS WILL CONTINUE TO MELT AND SEA LEVELS COULD RAISE ENOUGH TO FLOOD SOME LOW-LYING COASTAL AREAS STORMS COULD BECOME MORE FREQUENT AND SEVERE MORE SERIOUS DROUGHTS IN NORTH AMERICA ABUNDANCE OF DISEASE CARRYING SPECIES COULD INCREASE

112 THE VALUE OF A HEALTHY BIOSPHERE A HEALTHY BIOSPHERE PROVIDES US WITH VALUABLE GOODS AND SERVICES: + TEMPERATURE CONTROL + WATER PURIFICATION + SOIL FORMATION

113 The Value of a Healthy Biosphere Human society depends on healthy, diverse, and productive ecosystems because of the environmental and economic benefits they provide.

114 HOW DO WE MAINTAIN A HEALTHY BIOSPHERE? USE RESOURCES WISELY RECYCLE MATERIALS CONSERVE ENERGY BETTER INSULATE HOMES AND OFFICES BUY FUEL EFFICIENT CARS

115 Meeting Ecological Challenges Ecological Footprint: describes the total area of functioning land and water ecosystems needed to provide resources for an individual/population and to absorb harmless wastes from that individual/population

116 Meeting Ecological Challenges Ecological footprints help us determine what the carrying capacity is for humans and our own impact on the world No exact way to calculate it It is estimated that Americans footprints are four times larger than the global average we use too much!!

117 Meeting Ecological Challenges Steps to take action: 1. Recognize the problem in the environment 2. Research the problem to determine its cause 3. Use scientific understanding to change our behavior to have a positive impact on the global environment

118 Let s Meet A Challenge! In your table groups, design an ecologically sustainable house and draw it out on a piece of paper. You will have to explain the different things you ve added to the house that make it sustainable.

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