Directions: Be sure to make an electronic copy of your answer before submitting it to Ashworth College for grading. Unless otherwise stated, answer in complete sentences, and be sure to use correct English spelling and grammar. Sources must be cited in APA format. Your response should be four (4) pages in length; refer to the “Assignment Format” page for specific format requirements.
In your course, turn to Lesson 4. Skim through it to refresh your memory. Next, carefully study and review the section titled, “Ecological Challenges Facing Humanity.” Skim through that and then focus on the topic of deforestation.
Using your own words, write a short descriptive essay that defines and explains selected environmental impacts of deforestation. As you write, imagine you are talking to a friend who has no knowledge of this topic. In short, write the way you speak, using a conversational tone. Also, try to alternate short sentences and longer sentences to make your writing more readable.
Be sure to create a title and cite yourself as the author. For example:
Environmental Impacts of Deforestation
Your essay should include five paragraphs, as follows:
Paragraph 1 is your lead paragraph. It will contain an overview of what you have to say about these three topics: disruption of the carbon cycle, disruption of the hydrologic (water) cycle, and the reduction of species diversity.
Paragraphs 2, 3, and 4, are your body paragraphs.
Paragraph 2 should describe how deforestation disrupts the carbon cycle.
In paragraph 3, you’ll write about how deforestation disrupts the hydrologic (water) cycle.
In paragraph 4, you’ll explain how deforestation is related to declining species diversity.
Paragraph 5 is your conclusion paragraph. Here, you can describe how you feel about the three effects of deforestation discussed, and what we might do about it.
It’s permissible to use direct quotes from your reading, but don’t use too many. One to three such quotes should be your limit. Be sure to put a direct quote in quotation marks. For example: According to Smith, “Carbon dioxide is both our friend and our enemy.”
Begin by writing a first draft. Then, edit and rework your material to make it clear and concise. After you have reached a final draft, proofread the essay one last time to locate and correct grammar and spelling errors.
The Earth System
Earth is the third planet from the sun in our solar system. Earth orbits the sun in an elliptical (oval) path. Earth’s orbit is sometimes called the “Goldilocks zone.” Mercury and Venus travel too close to the sun to sustain life—they’re “too hot.” Planets beyond Earth travel too far from the sun—they’re “too cold.” But Earth is “just right.” (Note that there’s evidence that Mars—the Red Planet—once may have sustained microscopic life on its surface. However, conditions on the Red Planet no longer seem favorable.)
The term “Earth system” refers to the different processes and cycles that exist on the planet. All of these work together to sustain life. The four domains of the Earth system include the geosphere, the hydrosphere, the atmosphere, and the biosphere. Let’s quickly review each of these.
Layers of Earth
(NASA public domain image)
The geosphere refers to the solid portion of the planet. It includes the rocks and minerals that make up the continents as well as the ocean floor. It also includes structures within Earth, including the liquid mantle and the dense, solid, metallic core. Nonliving surface ground layers, such as desert sands and volcanic rock, are part of the geosphere.
The hydrosphere includes all the water on or near Earth’s surface. The oceans are the major component of the hydrosphere. They make up 97 percent of the Earth’s water. Glaciers and polar ice caps make up about 2 percent of the hydrosphere. Only about 1 percent of the hydrosphere is made up of the liquid freshwater found in ponds, streams, rivers, lakes, and underground water reservoirs (aquifers).
Aquifers are the main freshwater source in America’s “breadbasket” states of the Midwest and Great Plains. (“Breadbasket” states get their name from the volume of wheat, a primary ingredient in bread, grown there.) The hydrosphere extends several miles above the surface of the planet into the atmosphere, mainly in the form of water vapor.
Water vapor is water in its gaseous state. Precipitation is water released from the clouds. It may take the form of rain, freezing rain, sleet, snow, or hail. It’s part of the water cycle.
For more information on the hydrosphere, follow this link: What is the HYDROSPHERE?
The atmosphere is the planet’s blanket. It allows living beings on the planet to breathe. It also protects us from the unfriendly features of the universe, such as meteors, cosmic radiation, and the effects of solar flares.
The atmosphere is made up of a variety of layers, as follows:
(NASA public domain image)
The troposphere is the densest part of the atmosphere. It starts at Earth’s surface and extends upward from about 5 miles (in the higher or lower latitudes) to 9 miles (over the equatorial regions). Most of our weather takes place here.
The stratosphere extends from the troposphere upward about 31 miles. The ozone layer, which protects the planet from solar ultraviolet radiation, is located in this region.
The mesosphere starts just above the stratosphere. This layer is where most meteors burn up to become “falling stars.” It extends upward for about 53 miles.
The thermosphere extends from just above the mesosphere. It extends upward for about 372 miles. The thermosphere is the region where most human-made satellites orbit the planet. It’s also the location of the Aurora Borealis (the Northern Lights).
The ionosphere extends upward about 600 miles from the thermosphere. This layer gets its name because it includes electrons and assorted ions, allowing for radio communications on the planet. Broadcast signals are radio frequencies that are bounced off the ionosphere.
The exosphere extends from the ionosphere/thermosphere upward some 6,200 miles. This layer is the outer limit of Earth’s atmosphere.
For a more in-depth look at the atmosphere, access this site by NASA: Earth’s Atmospheric Layers
The biosphere is the layer of Earth where life exists. It includes all life on land, water, and in the air. The list of organisms living on Earth is long and complex. It includes all plants and fungi. It includes microscopic creatures like bacteria, viruses, and ocean plankton. And, of course, it includes all animals, including humans.
Want to review Earth’s system as an animated short? Check out this video: