Human Impact Study Guide

1.5 Human Impact (Bio.1.5)

Explore this Phenomenon

Wolverines are one species that is affected by human activities. Female wolverines need to make a den in snow to give birth. Human activities are causing the climate to change, which results in less territory for wolverines to live and give birth.

1. What are some possible solutions to this problem?
2. What other human activities affect ecosystems and biodiversity?
3. What solutions could be applied to help reduce the impacts of human activities on ecosystems?

 

Bio.1.5 Human Impact

Design a solution that reduces the impact caused by human activities on the environment and biodiversity. Define the problem, identify criteria and constraints, develop possible solutions using models, analyze data to make improvements from iteratively testing solutions, and optimize a solution. Examples of human activities could include building dams, pollution, deforestation, or introduction of invasive species. (LS2.C, LS4.D, ETS1.A, ETS1.B, ETS1.C)

Humans can cause changes to the environment and biodiversity. As you read this chapter, think about ways that we could reduce the impacts on ecosystems that are caused by our activities.

 

Human Activities Affect the Environment

What is involved in Engineering Design?

Engineering is a creative process where each new version of a design is tested and then modified, based on what has been learned up to that point. This process includes a number of stems:

1. Identifying the problem and defining criteria and constraints.
2. Generating ideas for how to solve the problem. Engineers can use research, brainstorming and collaboration with others to come up with ideas for solutions and designs.
3. Build and then test the prototypes. Using data collected, the engineer can analyze how well the various prototypes meet the given criteria and constraints.
4. Evaluate what is needed to improve the leading design or devise a better one.

 

Recall from the beginning of this section that female wolverines need to make a den in snow to give birth. As human activities cause the climate to change, wolverines have less territory to build dens. Your task is to design a solution to this problem.

To design a solution to the problem, you will need to start by identifying the criteria and constraints. Then develop several possible solutions. Once you have several possible solutions, use the criteria and constraints to evaluate each. You should test the solution that will best meet the criteria and constraints, and then determine how to improve the solution, based on test results. Testing the solution may include modeling, working with materials, using mathematical relationships, etc.

In this section, you will be learning about how human activities affect ecosystems and biodiversity. You will also be learning about some possible solutions. Think about how human activities are affecting ecosystems, and how realistic and effective different solutions for mitigating the effects are. When you finish this section, apply your experience evaluating possible solutions to designing and evaluating a solution to the problem of wolverines losing territory for their dens.

 

Water Pollution

Do you live near water? Do you see pollution?

Water pollution is a worldwide problem. Almost anything released into the air or onto the land can end up in Earth’s water.

Water pollution may come from one source. For example, chemicals from a factory may empty into a stream. Water pollution may come from more than one source, too. For example, chemicals may rain from the air into that same stream. It is much more difficult to control pollution from more than one source.

 

In the developed nations there are three main sources of water pollution:

1. Agriculture
2. Industry
3. Municipal, or community

 

 

Agriculture

Chemicals that are applied to farm fields include fertilizers and pesticides. Excess chemicals can be picked up by rainwater. The chemicals can end up in streams, ponds, lakes, or the ocean. Dissolved fertilizer causes tremendous numbers of water plants and algae to grow. This can lead to dead zones where nothing can live in lakes or the coastal oceans.

Waste from livestock can also pollute water. The waste contains pathogens that can cause diseases. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one pictured below. Many leaks from these lagoons have occurred.

This is a pond of hog manure. Check out the vehicles at the bottom of the picture for scale.

 

Industry

Factories and power plants may pollute water with harmful substances.

• Many industries produce toxic chemicals.
• Nuclear power plants produce radioactive wastes.
• Oil tanks and pipelines can leak.

Oil spills are hard to clean up and kill a lot of wildlife.

 

Municipal

“Municipal” refers to the community. Households and businesses in a community can pollute the water supply. Municipal pollution comes from sewage, storm drains, septic tanks, boats, and runoff from yards. For example:

• People apply chemicals to their lawns. The excess can run off into surface waters.
• People may dispose of harmful substances incorrectly. For example, motor oil must not be drained into a storm sewer.
• Municipal sewage treatment plants dump treated wastewater into rivers or lakes. But the wastewater may not be treated for everything, or it may not be treated well enough.

 

What are some solutions to water pollution? Inventor Adam Katzman is using natural processes to treat sewage.

Go to https://www.youtube.com/watch?time_continue=234&v=sjvN2vt3kbg to see his eco-friendly floating toilet, and evaluate his design solution.

 

Habitat Destruction

What's happening to this land?

This picture, taken in southern Mexico, shows land being cleared for agriculture. The forest has been cut down and burned to make room for a farm. In the process, homes to many plants and animals were destroyed. This is an example of habitat destruction.

From a human point of view, a habitat is where you live, go to school, and go to have fun. Your habitat can be altered, and you can easily adapt. Most people live in a few different places and go to a number of different schools throughout their life. But a plant or animal may not be able to adapt to a changed habitat. A habitat is the natural home or environment of an organism. Humans often destroy the habitats of other organisms. Habitat destruction can cause the extinction of species. Extinction is the complete disappearance of a species. Once a species is extinct, it can never recover. Some ways humans cause habitat destruction are by clearing land and by introducing non-native species of plants and animals.

 

Land Loss

Clearing land for agriculture and development is a major cause of habitat destruction. Within the past 100 years, the amount of total land used for agriculture has almost doubled. Land used for grazing cattle has more than doubled. Agriculture alone has cost the United States half of its wetlands and almost all of its tallgrass prairies. Native prairie ecosystems, with their thick fertile soils, deep-rooted grasses, diversity of colorful flowers, burrowing prairie dogs, and herds of bison and other animals, have virtually disappeared.

The Flint Hills contain some of the largest remnants of tallgrass prairie habitat remaining in North America.

Herds of bison also make up part of the tallgrass prairie community.

 

Slash-and-Burn Agriculture

Other habitats that are being rapidly destroyed are forests, especially tropical rainforests. The largest cause of deforestation today is slash-and-burn agriculture . This means that when people want to turn a forest into a farm, they cut down all of the trees and then burn the remainder of the forest. This technique is used by over 200 million people in tropical forests throughout the world.

As a consequence of slash-and-burn agriculture, nutrients are quickly lost from the soil. This often results in people abandoning the land within a few years. Then the top soil erodes and desertification can follow. Desertification turns forest into a desert, where it is difficult for plants to grow. Half of the Earth’s mature tropical forests are gone. At current rates of deforestation, all tropical forests will be gone by the year 2090.

What are some ways that we could either reduce the amount of habitat that is destroyed, or mitigate the effects of habitat destruction on other species? Scientists and engineers are developing ways to use resources more sustainably.

Watch https://www.youtube.com/watch?time_continue=10&v=eEFwaQej_0E to learn about and evaluate some sustainable development solutions.

 

Oil Spills

 

Can you see the oil in a big oil spill?

Oil rigs are built in the oceans to get at oil buried beneath the seafloor. These rigs pump oil from beneath the ocean floor. Huge ocean tankers carry oil around the world. If something goes wrong with a rig or a tanker, millions of barrels of oil may end up in the water. The oil may coat and kill ocean animals. Some of the oil will wash ashore. This oil may destroy coastal wetlands and ruin beaches.

New drilling techniques allow oil companies to drill in deeper waters than ever before. In April 2010 a rig in the Gulf of Mexico exploded. Eleven workers were killed and 17 injured. When the drill rig sank, a pipe was disconnected and oil gushed into the Gulf. Three months later the well was capped. But 4.9 million barrels had entered the Gulf, about 16 times more oil than the largest oil spill to date.

 

Cleanup

Once the oil is in the water, there are three ways to try to clean it:

1. Removal: Corral and then burn the oil.
2. Containment: Use containment booms to trap the oil.
3. Dispersal: Use chemicals to get the oil to disperse, called chemical dispersants.

Some scientists think that the harm to the environment from the dispersants is as great as the harm from the oil. The total effect of the oil spill on the environment of the Gulf is not yet known. Oil is found in the sediments on the seafloor. Many people who fish or are involved in Gulf tourism were also impacted. Studies of the effects of the oil spill on people and animals will continue for many years.

 

Mining

Can you tell that this was mine?

Mining can do a lot of damage to a region. Mining companies are now supposed to return the land to its natural state when they are done. Sometimes this works really well. It's hard to tell there was a mine here!

Mining provides people with many resources they need. But mining can be hazardous to the environment. For surface mines, miners clear the land of soil and plants. Nearby lakes and streams may be inundated with sediment. The mined rock may include heavy metals. These also enter the sediment and water. Removing metals from rock may involve toxic chemicals. Acid flow from a mine site will change the chemistry of a nearby stream or lake.

 

Mine Pollution

Mining can cause pollution. Chemicals released from mining can contaminate nearby water sources. Pictured below is water that is contaminated from a nearby mine. The United States government has mining standards to protect water quality.

This water has been polluted by a mountaintop removal mine.

 

Land Reclamation

One way that scientists and engineers have tried to mitigate the effects of mining is to reclaim the land. U.S. law states that once mining is complete, the land must be restored to its natural state. This process is called reclamation. A pit may be refilled with dirt. It may be filled with water to create a lake. The pits may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. The land is reshaped. Native plants are planted .

 

Putting It Together

Wolverines are one species that is affected by human activities. Female wolverines need to make a den in snow to give birth. Human activities are causing the climate to change, which results in less territory for wolverines to live and give birth.

1. As we develop solutions to mitigate the effects of human impacts, we will also have to develop criteria. What criteria should our solutions meet?
2. One solution that has been proposed is to create a corridor to increase habitat for wolverines. Evaluate the solutions proposed in this video: https://www.ck12.org/biology/habitat-destruction/rwa/Wheres-My-Snow-Den/?referrer=concept_details

3. What are some other solutions that could be used to mitigate the effects of human impacts on wolverines?
4. Evaluate each of the solutions you created for question two using the criteria you developed for question one. Which solutions meet the criteria?