Earth’s Human Population Continues to Grow Earth’s human carrying capacity is unknown Technology has helped to increase Earth’s carrying capacity. gas-powered farm equipment medical advancements clean water public assistance
The Big Problem: Overpopulation • Over 6.6 billion people • Many natural resources are nonrenewable • Fossil fuels take millions of years to form • More people means: • 1) More forests removed • 2) More resources consumed • 3) More CO2 released
The growing human population = pressure on Earth’s natural resources • Nonrenewable resources are used faster than they can form or be replenished: • Coal • Oil • Natural Gas MUST BE MANAGED EFFECTIVELY!!! • Renewable resources cannot be used up or can replenish themselves over time : • Wind • Solar • Water
The land must produce and maintain enough • food and water • shelter • energy • Waste • Several factors effect size: • Amount/efficiency of resource used • Amount/toxicity of waste produced • An ecological footprint is the amount of land needed to support a person.
What are some Environmental issues Caused by human activity?
Ozone Layer Depletion Ozone Function: Block UV radiation from sun Problems: CFCs thinning the ozone layer More UV radiation reaches the surface Effects: Crop damage, skin cancers, Eye damage Solution: Reduce CFCs, regrow trees UV UV Ozone layer Ozone layer CFCs
The Smog and Ground-Level Ozone Reason: Burning of fossil fuels & industry Problems: Respiratory illness Ozone gas is poisonous Causes: Particulates rise into air and react with sunlight to make air pollution Solutions: Reduce use of fossil fuels alternative energy sources Plant trees
The Greenhouse Effect G.H.E. is naturally good (it warms Earth) Problem: Excess heat trapped near the earth’s surface Fear: Climate patterns change, ice caps melt Main Cause: CO2 from burning of fossil fuels (coal, oil, natural gas) Solutions: Reduce use of fossil fuels, regrow trees, alternative energy sources
What’s a Greenhouse? A Greenhouse is designed to trap heat so you can grow plants year round, even in cooler environments. heat Some heat escapes the greenhouse, but enough is trapped to keep the inside warm heat heat heat
Some heat escapes into space heat Some heat naturally trapped by Earth’s atmosphere The Natural Greenhouse Effect is good! heat heat Earth The Atmosphere
Less heat escapes into space heat heat heat More heat trapped near Earth’s surface heat heat Excess CO2 in atmosphere Earth
The Greenhouse Effect is naturally GOOD! Mars: No Greenhouse Effect Earth: Balanced Greenhouse Effect Venus: The Extreme Greenhouse Effect Little 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.
Defined: Precipitation with a below normal pH Cause: Fossil fuel pollution rises into the air & then falls as rain Effect: Waterways more acidic Kills plant and animal life Solutions: Reduce fossil fuel usage Add buffer (base) to waterways Acid Rain
Nitric acid Sulfuric acid SO2 NO NO
Water pollution • Defined: pollution in water supplies • Causes: • Waste • Medicines • Agricultural Runoff • fertilizers • pesticides • Problems: • Species lost • Ecosystems harmed • Solutions: • Manage waste
Water pollution affects ecosystems • Indicator species: Give sign of ecosystem’s health • Example: • Amphibians • Frogs are good indicator species because their skin is water permeable. • Top predators • Solution: Waste Management
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 organism • predators eat contaminated prey • Pollution accumulates at each stage of the food chain • Top consumers, including humans, are most affected.
Deforestation Defined: Clearing of forested areas Reasons: High demand for wood products Create farmland Problems: Species lost Excess CO2 released Solutions: Recycle Improved farming techniques
Introduced (& Invasive) Species Zebra mussels Mice Kudzu vines • Defined: Foreign organisms are introduced to a new habitat • Invasive- harms native species • Reason: • Pet industry, “free ride” organisms, pest control • Effects: • Foreign species outcompete native species • Food webs unbalanced • Economic damage • Solutions: • Laws preventing foreign goods into new countries • Introduce predators
What is being done? • The Environmental Protection Agency (EPA) • Created in 1970 • Works to protect species • Clean Water Act • Clean Air Act • Endangered Species Act • This recovered the bald eagle) • Those listed are called “Umbrella Species” • Entire habitats protected
Review • CFCs 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?