2 Earth’s Human Population Continues to Grow Technology has helped to increase Earth’s carrying capacity.Earth’s human carrying capacity is unknowngas-powered farm equipmentmedical advancementsclean waterpublic assistance
3 The Big Problem: Overpopulation Over 6.6 billion peopleMany natural resources are nonrenewableFossil fuels take millions of years to formMore people means:1) More forests removed2) More resources consumed3) More CO2 released
5 The growing human population = pressure on Earth’s natural resources MUST BE MANAGED EFFECTIVELY!!!Nonrenewable resources are used faster than they can form or be replenished:CoalOilNatural GasRenewable resources cannot be used up or can replenish themselves over time :WindSolarWater
6 An ecological footprint is the amount of land needed to support a person. The land must produce and maintain enoughfood and watershelterenergyWasteSeveral factors effect size:Amount/efficiency of resource usedAmount/toxicity of waste produced
7 Caused by human activity? What are someEnvironmental issuesCaused by human activity?
8 Ozone Layer Depletion Ozone Function: Block UV radiation from sun Problems:CFCs thinning the ozone layerMore UV radiation reaches the surfaceEffects: Crop damage, skin cancers, Eye damageSolution: Reduce CFCs, regrow treesUVUVOzone layerOzone layerCFCs
9 The Smog and Ground-Level Ozone Reason:Burning of fossil fuels & industryProblems:Respiratory illnessOzone gas is poisonousCauses:Particulates rise into air and react with sunlight to make air pollutionSolutions:Reduce use of fossil fuelsalternative energy sourcesPlant trees
10 The Greenhouse Effect G.H.E. is naturally good (it warms Earth) Problem: Excess heat trapped near the earth’s surfaceFear: Climate patterns change, ice caps meltMain Cause: CO2 from burning of fossil fuels (coal, oil, natural gas)Solutions: Reduce use of fossil fuels, regrow trees, alternative energy sources
11 What’s a Greenhouse?A Greenhouse is designed to trap heat so you can grow plants year round, even in cooler environments.heatSome heat escapes the greenhouse, but enough is trapped to keep the inside warmheatheatheat
12 Earth Some heat escapes into space heat Some heat naturally trapped by Earth’s atmosphereThe Natural Greenhouse Effect is good!heatheatEarthThe Atmosphere
14 Earth Less heat escapes into space heat heat heat More heat trapped near Earth’s surfaceheatheatExcess CO2 in atmosphereEarth
15 The Greenhouse Effect is naturally GOOD! Mars: No Greenhouse EffectEarth: Balanced Greenhouse EffectVenus: The Extreme Greenhouse EffectLittle heat is trapped by the thin CO2 atmosphere. High temperatures can be around 20⁰F.Heat is trapped by the thick CO2 atmosphere. Temperatures reach 750⁰F.Average global temperature is 57⁰F.
16 Acid Rain Defined: Precipitation with a below normal pH Cause: Fossil fuel pollution rises into the air & then falls as rainEffect:Waterways more acidicKills plant and animal lifeSolutions:Reduce fossil fuel usageAdd buffer (base) to waterways
20 Water pollution Defined: pollution in water supplies Causes: Waste MedicinesAgricultural RunofffertilizerspesticidesProblems:Species lostEcosystems harmedSolutions:Manage waste
21 Water pollution affects ecosystems Indicator species: Give sign of ecosystem’s healthExample:AmphibiansFrogs are good indicator species because their skin is water permeable.Top predatorsSolution: Waste Management
22 Biomagnification = Accumulation of toxins in the food chain Pollutants that are fat soluble can move up the food chain.These pollutants stay in the body fat of an organismpredators eat contaminated preyPollution accumulates at each stage of the food chainTop consumers, including humans, are most affected.
23 Deforestation Defined: Clearing of forested areas Reasons: High demand for wood productsCreate farmlandProblems:Species lostExcess CO2 releasedSolutions:RecycleImproved farming techniques
25 Introduced (& Invasive) Species Defined: Foreign organisms are introduced to a new habitatInvasive- harms native speciesReason:Pet industry, “free ride” organisms, pest controlEffects:Foreign species outcompete native speciesFood webs unbalancedEconomic damageSolutions:Laws preventing foreign goods into new countriesIntroduce predatorsZebra musselsMiceKudzu vines
26 What is being done? The Environmental Protection Agency (EPA) Created in 1970Works to protect speciesClean Water ActClean Air ActEndangered Species ActThis recovered the bald eagle)Those listed are called “Umbrella Species”Entire habitats protected
27 ReviewCFCs are manmade chemical responsible for the destruction of _________________.Which gas is a main contributor to the greenhouse effect?Crop damage and cancers are caused by an excess amount of which type of energy?Name the big three fossil fuels.Which planet has excess temperatures because of a thick CO2 atmosphere?Desert-like land is created as a result of which problem?Where is ozone gas harmful to life?Where is ozone gas helpful to life?Food webs become unbalanced as a result of the introduction of which type of organisms?Even though there may be space for people, why do those who study the environment consider humans to be overpopulated?