Environmental ImpactsThe Impact of Plastic Bags in the Environment

The Water Cycle• Only way that Earth can be supplied with fresh water

How does this happen?• Heat soaks up water from the oceans lakes, rivers, trees and plants in a process called evaporation.

• Water mixes with the air it forms water vapor. As the air cools, the water vapor forms clouds. This is called condensation.

• Water vapor is carried inside clouds by wind over land and water and is released as rain or snow (precipitation).

• Rain and melted snow is brought back to the oceans by rivers, streams, and run-off from glaciers and water underground.

The Water Cycle

The Cycling of Matter The cycling of matter is a series of steps in a cycle that allows

nonliving (abiotic) elements to be used over and over again. Carbon, nitrogen, and phosphorus atoms are basic elements of

matter that are cycled in ecosystems. Cycling interactions are part of the constant change in

ecosystems. Producers are plants that make energy from using the sun, water

and carbon dioxide. These inorganic elements are turned into organic compounds, like sugar.

Herbivores are animals that eat only plants (Primary Consumers) Carnivores are animals that eat only other animals (Secondary or

Tertiary Consumers) Omnivores are animals that eat both plants and other animals

(Secondary or Tertiary Consumers) Decomposers break down organic matter from plants and

animals in order to recycle basic elements.

The Cycling of Matter

Humans in the Food Chain

Environmental Impacts Plastic bags are so cheap to produce, sturdy, plentiful, easy to

carry and store What happens to plastic bags once they get home? Many bags are reused as book and lunch bags, as trash can

liners, and to pickup dog droppings off the lawn Sit balled up and stuffed into the one that hangs from the

pantry door, line bathroom trash bins, carry clothes to the gym, clutter landfills, flap from trees, float in the breeze, clog roadside drains, drift on the high seas and fill sea turtle bellies

United States Environmental Protection Agency in 2001: Between 500 billion and a trillion plastic bags are consumed worldwide each year. Millions end up in the litter

stream outside of landfills When they are thrown out or littered, as they decompose, tiny toxic bits seep into soils, lakes, rivers, and the oceans

Environmental Impacts The Great Pacific Garbage Patch is a collection of debris in the North Pacific

Ocean. The Pacific Ocean Garbage Patch is created by an ocean gyre, which is a circular

ocean current formed by the Earth’s wind patterns and the forces created by the rotation of the planet.

The circular motion of the gyre draws in debris. Debris eventually makes its way into the center of the gyre, where it becomes trapped and builds up.

The Pacific Ocean Garbage Patch disturbs marine food webs Plastics and other trash collect on the surface of the ocean and blocks sunlight

from reaching plankton and algae below Animals, such as fish and turtles, feed on algae and plankton have less food,

they often mistake plastic bags as a source of food. Many marine species in this area have stomachs filled with small pieces of plastic because the concentration of plastic is 6 times greater then then concentration of plankton and algae If those animals start to die, there will be less food for predator species such as tuna, sharks, whales and humans.

Environmental Impacts

Environmental ImpactsFacts About Plastic Bags• Plastic bags are made from petroleum, a non-renewable fossil resource• Each person uses about 350 bags every year• Each bag is used for only about 20 minutes • Each bag takes nearly 400 years to break down

Alternatives to Plastic Bags• Looks like plastic BUT its made from organic material and breakdown in about 45 days• The paper bag. Biodegrades quickly, but its production requires a great deal of water.• Reusable bags. Made from cloth and canvas. They are durable and can be reused many times However, they consume large amount of energy and resources to produce.

Environmental Impacts• Toronto had banned the use of plastic bags! How will this help?

• Reduce the amount of plastic bags in the environment• Help decrease the amount of toxins from decomposing plastics from entering environment

• What about other plastics?

ABC News Nightline: Plastic Garbagehttp://www.youtube.com/watch?v=8a4S23uXIcM

Fold The Line! Is there enough being done to deal with

the environmental impacts caused by plastic bags?

Choose a position: Yes, No, Maybe. Distribute yourself across the room. Yes, enough No, enough is being done is being done.

References: Science and Technology 7. Nelson. 2000. Pg. 266, 267,274, 275, 278, 279.

Plastic bag ban, environmental perspectivehttp://www.thestar.com/news/gta/article/1213864--reality-check-will-a-plastic-bag-ban-actually-help-the-environment

Environment Canada on plastic bagshttp://www.ec.gc.ca/biosphere/default.asp?lang=en&n=09AC4A1B-1

National geographic on plastic bags http://news.nationalgeographic.com/news/2003/09/0902_030902_plasticbags.html

Great pacific garbage patchhttp://education.nationalgeographic.com/encyclopedia/great-pacific-garbage-patch/?ar_a=1