Human Impact on Ecosystems
Earth’s Human Population Continues to Grow
Technology has helped to increase Earth’s carrying capacity. Earth’s human carrying capacity is unknown gas-powered farm equipment medical advancements clean water public assistance
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
MUST BE MANAGED EFFECTIVELY!!!
Earth’s Natural Resources The growing human population puts pressure on Earth’s natural resources MUST BE MANAGED EFFECTIVELY!!! Nonrenewable resources are used faster than they can form or be replenished: Coal Oil Natural Gas Renewable resources cannot be used up or can replenish themselves over time : Wind Solar Water
Ecological Footprint Defined: the amount of land needed to support a person. 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
Caused by human activity?
What are some Environmental issues Caused by human activity?
Ozone Layer Depletion Cause: Effects: Solution: Ozone Function: Block
UV radiation from sun Cause: CFCs (air pollution) thin the ozone layer More UV radiation reaches the surface Effects: Crop damage Skin cancers Eye damage Solution: Reduce/Regulate CFCs Plant trees UV UV Ozone layer Ozone layer CFCs
Smog and Ground-Level Ozone
Causes: Burning of fossil fuels & industry Particulates rise into air and react with sunlight to make air pollution Effects: Ozone gas (O3)is poisonous Respiratory illness Solutions: Reduce use of fossil fuels Alternative energy sources Plant trees
The Greenhouse Effect G.H.E. is naturally good (it warms Earth)
Causes: CO2 from burning of fossil fuels (coal, oil, natural gas) Effects: Excess heat trapped near the earth’s surface may change global climate patterns; ice caps melt Solutions: Reduce use of fossil fuels, plant 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
Earth Some heat escapes into space CO2 heat
Some heat naturally trapped by CO2 and other greenhouse gases CO2 heat The Natural Greenhouse Effect is good for life on Earth. heat heat CO2 CO2 CO2 CO2 CO2 heat CO2 CO2 CO2 Earth CO2 CO2
CO2, Methane, other greenhouse gases
Earth More heat trapped near Earth’s surface
Less heat escapes into space CO2 heat CO2 heat heat heat heat CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 heat CO2 CO2 CO2 CO2 CO2 CO2 CO2 CO2 Excess CO2 in atmosphere CO2 CO2 CO2 CO2 CO2 Earth CO2 CO2 CO2 CO2
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.
Acid Rain Defined: Precipitation with a below normal pH Cause:
Fossil fuel pollution rises into the air & then falls as rain Effects: Waterways more acidic Kills plant and animal life Solutions: Reduce fossil fuel usage Add buffer (base) to waterways
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 Defined: Accumulation of toxins in the food chain
Fat soluble pollutants move up food chain. These pollutants stay in the body fat of an organism Predators eat contaminated prey Pollution accumulates at each level of the food chain Top consumers, including humans, are most affected.
Deforestation Defined: Clearing of forested areas
Causes: Harvesting/destroying forests for high demand: Wood products Creating farmland Effects: Species lost Excess CO2 released Solutions: Recycle Improved farming techniques
Introduced & Invasive Species
Defined: Foreign organisms are introduced to a new habitat Invasive: harms native species Cause: Foreign species introduced to new environment Effects: Foreign species outcompete native species Food webs unbalanced Economic damage Solutions: Laws preventing foreign goods into new countries Introduce predators Zebra mussels Mice Kudzu vines
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 the 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? What is smog? How are pollutants passed through the food chain? Where is ozone gas harmful to life? Where is ozone gas helpful to life? What makes a resource nonrenewable? Food webs become unbalanced as a result of the introduction of which type of organisms? What is an umbrella species?
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