Human Impact on the Environment

Human Impact on the Environment

Middle School

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Learning Objectives

• Identify human activities that change ecosystems and describe their different effects.

• Explain biodiversity and its importance for a healthy and balanced ecosystem.

• Compare renewable and nonrenewable resources and their effects on the environment.

• Analyze the pros and cons of different energy sources for our planet.

Key Vocabulary

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Anthropogenic Changes

Significant environmental changes that are directly caused by various human activities.

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Invasive Species

Non-native animals or plants that invade and negatively affect the habitats they enter.

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Overexploitation

When land is over-farmed or overgrazed, it removes essential nutrients from the soil.

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Climate Change

A significant, long-term change in the common weather patterns of a specific area.

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Biodiversity

The variety of different species of plants and animals found in a specific ecosystem.

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Speciation

The natural evolutionary process that results in the formation of an entirely new species.

Key Vocabulary

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Nonrenewable Resources

Natural resources, such as fossil fuels, that are used up faster than they can be replaced.

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Renewable Resources

Resources like wind, sun, or water that are naturally replenished over a short period.

Human Impact on Ecosystems

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Habitat Destruction

• Natural habitats are cleared to build farms, roads, and houses.

• This widespread clearing of forests is commonly known as deforestation.

• This can cause the population of many native species to decrease.

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Pollution

• Harmful gases, like sulfur oxides, from factories cause air pollution.

• Water gets polluted by chemical runoff containing oil and fertilizers.

• This pollution can severely harm or kill many local species.

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Invasive Species

• These are non-native species introduced into a new ecosystem.

• They compete with native species for food, water, and space.

• This competition negatively harms the survival of native species.

Multiple Choice

What is the term for the widespread clearing of natural habitats, like forests, to build farms, roads, and houses?

• Invasive Species

• Ecosystem Competition

• Pollution

• Deforestation

Multiple Choice

What is the primary way that invasive species harm native species in an ecosystem?

• By helping them find new sources of food

• By competing with them for essential resources

• By polluting the air and water supply

• By clearing away the natural habitat

Multiple Choice

A new factory is built near a forest, leading to the clearing of many trees. The factory also releases chemical runoff into a nearby river. Which of the following is the most likely combination of impacts on the local ecosystem?

• Native species will have more space to live, and the river water will become cleaner.

• Non-native species will be introduced, and the air quality will improve.

• The number of trees will increase, and native species will have more food.

• The population of native species will decrease, and the river water will become polluted.

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What Are Anthropogenic Changes?

• The human population of over 8 billion strains the planet's natural resources.

• Human activities can lead to the overexploitation of land through excessive farming.

• This strips the land of essential nutrients, which can harm the ecosystem.

• Climate change is a long-term weather shift caused by human activity.

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Multiple Choice

Which of the following best defines an anthropogenic change?

• The natural process of land losing nutrients over time

• An increase in the total human population

• A long-term shift in weather patterns

• A change to the planet caused by human activities

Multiple Choice

How does the overexploitation of land through excessive farming affect the ecosystem?

• It removes essential nutrients the ecosystem depends on

• It causes a long-term shift in the planet's weather

• It helps to support a larger human population

• It increases the number of resources available

Multiple Choice

What is the most likely underlying cause for both climate change and the overexploitation of land?

• The strain on Earth's resources from a large human population

• The natural cycles of the planet's ecosystems

• The stripping of essential nutrients from the soil

• A long-term shift in global weather patterns

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The Importance of Biodiversity

• Biodiversity is the variety of species within a specific ecosystem.

• New species increase biodiversity, while extinction of species can decrease it.

• A diverse ecosystem is healthier and can better withstand threats like diseases.

• It provides beautiful landscapes for recreation, such as in national parks.

Multiple Choice

What is biodiversity?

• The creation of new national parks for recreation.

• The process of species becoming extinct.

• The variety of life within a specific ecosystem.

• The health of a single species in an ecosystem.

Multiple Choice

What is the relationship between extinction and biodiversity?

• Extinction has no effect on an ecosystem's biodiversity.

• Extinction decreases biodiversity by reducing the variety of life.

• Extinction increases biodiversity by creating new species.

• Extinction makes an ecosystem healthier.

Multiple Choice

A forest ecosystem loses several of its species due to pollution. What is the most likely consequence of this decrease in biodiversity?

• The ecosystem will become more beautiful for recreation.

• The ecosystem will be better able to withstand future threats.

• New species will immediately be created to replace the old ones.

• The ecosystem will become less healthy and less able to withstand future threats.

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Renewable vs. Nonrenewable Resources

Renewable Resources

• ​These resources, like wind, sun, and water, are naturally replenished by nature and will not run out.

• ​​Most are better for the environment as they are not burned to create energy, which avoids pollution.

• ​An exception is biofuels, like ethanol, which can create some pollution when they are burned for energy.

Nonrenewable Resources

• ​These resources, such as fossil fuels and coal, are limited and can be completely used up.

• ​​Extracting and burning them releases harmful chemicals that pollute the land, air, and water.

• ​Our society's technology relies heavily on them, making a switch to renewable energy very costly.

Multiple Choice

What is the primary difference between renewable and nonrenewable resources?

• Renewable resources cause pollution, while nonrenewable resources do not.

• Renewable resources are naturally replenished, while nonrenewable resources are limited.

• Renewable resources include fossil fuels, while nonrenewable resources include wind and sun.

• Renewable resources are more expensive than nonrenewable resources.

Multiple Choice

Why are renewable resources like wind and sun often considered better for the environment than nonrenewable resources?

• They generally do not release harmful pollutants when used for energy.

• They are available in more locations around the world.

• They are less expensive to extract from the earth.

• They can be used up completely, preventing future waste.

Multiple Choice

Given the environmental problems caused by nonrenewable resources, why does our society face challenges in switching completely to renewable energy?

• The technology and infrastructure for renewable energy are very expensive to implement.

• Nonrenewable resources are naturally replenished and will never run out.

• Renewable energy sources like wind and sun are not powerful enough for society's needs.

• Renewable resources like biofuels create more pollution than all fossil fuels.

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Common Misconceptions

Misconception	Correction
Introducing a new species to a habitat is always good for biodiversity.	Invasive species can harm ecosystems by outcompeting native species.
All renewable energy is 100% clean and pollution-free.	Some biofuels can create pollution when they are made and used.
We only use fossil fuels because other energy sources don't exist.	Renewable energy can be more costly to start than fossil fuel systems.

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Summary

• Human activities like pollution and habitat destruction disrupt ecosystems.

• Biodiversity, the variety of life, is vital for a healthy ecosystem.

• Resources are either renewable or nonrenewable, which are limited.

• Managing resources and switching to renewable energy are key for sustainability.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

• 1

• 2

• 3

• 4