3 Environmental Science: Is a interdisciplinary field of science that draws from many sciences (as well as other fields)Ex. Biology, chemistry, ecology,geology, earth science, geographyIs considered an applied science.Focuses on three main areas:conservation and protection of natural resourcesenvironmental education and communicationenvironmental researchThe environment is everything around us- in the natural world as well as things produced by humans.Environmental science is: the study of the impact of humans on the environment.Fields: ecology , biology (how to preserve species) , chemistry (helps us understand pollutants) , geology (helps us understand how pollutants travel underground) , geography (relationship between human populations and Earth’s features)Ecology: the study of how living things interact with each other and with their nonliving environment
4 Biodiversity: Renewable Resource: The number and variety of species that live in the area.Earth has been home to millions of species. Yet only a fraction of those species are alive today.Mass Extinction:Large scale extinction (some natural and some man made)A resource that can be replaced relatively quickly by natural processes.ex. Fresh water, air soil, trees, cropsNonrenewable Resource:A resource that forms at a much slower rate than it is consumedAt the end of the Permian period, 250 million years ago, as much as 95% of all species became extinct. Example: The Tasmanian tiger, native to an island near Australia was declared extinct in Dinosaurs.Why do we care? These organisms are natural resources. If it is extinct, it is a nonrenewable resources.Renewable resources can become nonrenewable when they are over-used (ex: trees)Nonrenewable resources are considered to be “depleted” when a large fraction of the resource has been used up.
5 Agriculture: Agriculture Revolution: The practice of growing, breeding, and caring for plants and animals that are used for food, clothing, housing, transportation, etc.Dramatic changes that impacted human societies and their environment when man began practicing agriculture more than 10, 000 years ago.Closed System:Earth has been compared to a “spaceship” traveling through space, unable to dispose of waste or take on new supplies as it travels.The only thing that enters Earth’s atmosphere in large amounts is energy from the sun.The only thing that leaves is heat.
6 Species ExtinctionThree popular theories as to how and why the megafauna (extremely large animals) ceased to exist in North America:The blitzkreig (overkill) : they were over huntedRapid climate shifts associated with the last ice ageDisease (similar to influenza or rabies) wasintroduced with the arrival of humansMegafauna in North America: mammoths, camels, giant ground sloths, beavers as large as bears, saber-toothed cats, maned lions, giant short-faced bears, dire wolves6
7 Hunter-GathersPeople who obtain food by collecting plants and by hunting wild animals / scavenging their remainsUsually migrated from place to placeStill some remain in Amazon rain forestCleared grassland by setting firesWhy did they set fires? They wanted to burn the prairies and prevent the growth of trees to keep the prairies and open grassland where they could hunt bison.Hunter-Gathers over hunted some large species of mammals such as giant sloths, giant bison, mastodons, saber-toothed cats, etc. and may have lead to their extinction.
8 Impacts made by the hunter-gatherers Changed the landscape by moving plants.Skeletal remains of hunter-gatherers from as many as 20, 000 years ago show signs that these humans were responsible for the pollutions of their environment and even suffered deformities as a result.Hunter-gathers began to collect seeds and domesticate some of the animals in their environment. This lead them to introduce new plants (non-native species).
9 Agricultural Revolution Caused human population growth, habitat loss, soil erosion, domestication of plants and animalsChanged the food we eatGrasslands, forest, and wetlands were replaced with farmland (**habitats were destroyed)Caused floods, water shortage, infertile soilAgriculture is the practice of growing, breeding, and caring for plants and animals that are used for food, clothing, housing, transportation, etc. Started in different parts of the world about 10,000 years ago.An area of land can support up to 500 times as many people by farming as it can by hunting and gathering! Populations began to concentrate in smaller areas.Slash-and-burn agriculture was used to convert forests to farmland. Done on a large scale this can cause soil loss, floods and water shortages.Farming was done poorly (overworked) and the soil becomes infertile.
10 Industrial Revolution Few restrictions were placed on air pollution during I.R. (burning of fossil fuels became extensive – leading to major pollution)Humans and animals had powered tools for almost10, 000 years (prior to I.R.) now machines do.Greatly increased the efficiency of agriculture, industry, and transportationUrban areas grew –people moved from farmsIndustrial Revolution occurs in the middle of the 1700s. Shift from energy sources such as animals and running water to fossil fuels such as coal and oil.
11 Main Environmental Issues Resource depletionPollutionLoss of biodiversity-The human population has been able to grow must faster (due to modern medicine and sanitation) resource depletion-Produce waste faster than they can be disposed of. Pollution is an undesired change in air, water, or soil that adversely affects the health, survival, or activities of humans or other organisms.
13 “The Tragedy of the Commons” Written by Garrett Hardin (in 1968)Influential essayDescribed the relationship between the short-term interest of the individual and the long-term interest of societyOverall point is that someone or some group has to take responsibility for maintaining a resourceSheep in field.“If I don’t use this resource, someone else will.”
14 Earth’s Shared Commons are our “Natural Resources” Anything within the “Biosphere”World’s Oceans / Waterways ; Air ; Migrating Animals ;Forest ; Fossil Fuels / Nuclear Materials
15 Economics and the Environment Supply and Demand: the greater the demand for a limited supply of something, the more it’s worth.Pay higher price, use less of _____ (oil), or find a new source of whatever that product provides (energy).
16 Economics and the Environment Continued Cost benefit analysis: balances the cost of the action against the benefits one expects from it.The cost of environmentalregulations are often passedon to the consumer.“The cost to clean up after an oilspill is added to the price of gas”Risk Assessment: a tool tohelp create cost-effectiveways to protect our healthand the environment.To an industry, the cost of pollution control may outweigh the benefits, but to a nearby community, the benefits may be worth the high price.Cost-benefit analysis involves risk assessment. To come up with an effective solution, the public must perceive the risk accurately. This does not always happen.
17 Developed v’s Developing Countries Developed Country: have higher average incomes, slower population growth, diverse industrial economies, stronger support systems.Include US, Canada,Japan, and the countriesof Western EuropeDeveloping Countries: loweraverage incomes, simple andagricultural-based economies,and rapid population growth.
18 Population and Consumption Environmental problems indeveloped countries tendto be related to consumption.The major environmentalproblems in developingcountries are related topopulation growth.Developed nations use about 75% of the world's resources, even though they make up only about 20% of the world’s population.
19 Ecological FootprintShows the productive area of Earth needed to support one person in a particular country.It estimates the land used for crops, grazing, forest products, and housing.It also estimates the ocean area used to harvest seafood and the forest are needed to absorb the air pollution.
20 A Sustainable WorldSustainability: the condition in which human needs are met in such a way that a human population can survive indefinitely.Is a primary goal of environmentalist.Fishing hole example.