Use evidence to explain how resource consumption affects Earth systems - Middle School Earth and Space Science

SECTION 1

Why Scientists Started Tracking Resource Use

People have always used Earth's natural resources (materials from nature that humans need or want). Wood, water, soil, and minerals helped early civilizations grow. For most of history, there were not enough people to use resources faster than Earth could replace them. That started to change a few hundred years ago.

During the Industrial Revolution, factories burned huge amounts of fossil fuels (coal, oil, and natural gas formed from ancient organisms). Smoke darkened city skies. Rivers turned colors from factory waste. Scientists began to wonder: could human activity change Earth's systems on a large scale?

1760s • The Industrial Revolution Begins

Factories in England start burning coal to power machines. Large-scale resource consumption begins, and air pollution rises sharply in cities.

1896 • CO₂ and Temperature Link Discovered

Swedish scientist Svante Arrhenius calculates that burning fossil fuels could warm the planet by adding carbon dioxide (CO₂) to the atmosphere.

1958 • Keeling Curve Measurements Begin

Charles David Keeling starts measuring atmospheric CO₂ in Hawaii. His data shows a steady rise each year, providing direct evidence that CO₂ is increasing.

1970 • First Earth Day

Twenty million Americans rally for cleaner air and water. The event leads to the creation of the Environmental Protection Agency (EPA) and new pollution laws.

2015 • Paris Climate Agreement

Nearly 200 countries agree to reduce fossil fuel use and limit global warming. This agreement relies on decades of scientific evidence about resource consumption and Earth's climate.

Today we have mountains of data — ice cores, satellite images, and ocean temperature records. The big question this lesson explores is: What evidence shows that our resource consumption affects Earth's atmosphere, water, and land?

SECTION 2

Core Principles of Resource Consumption and Earth Systems

Before we dig into the evidence, you need to understand a few key ideas. Earth works as a set of connected systems (groups of parts that interact and work together). When we change one system, the effects can ripple through the others.

Earth's Four Spheres

Earth has four main systems: the atmosphere (air), hydrosphere (water), geosphere (land and rock), and biosphere (living things). All four interact constantly.

Renewable vs. Nonrenewable Resources

Renewable resources (like sunlight and wind) are replaced naturally in a short time. Nonrenewable resources (like coal and oil) take millions of years to form. Using them up faster than they form causes lasting changes.

Cause and Effect in Earth Systems

When people burn fossil fuels, the cause is extra greenhouse gases entering the atmosphere. The effect is a warming climate. Cause-and-effect thinking is a powerful scientific tool.

Evidence-Based Reasoning

Scientists rely on evidence (data collected through observation and measurement) to support claims. Graphs, measurements, and patterns in data are all types of evidence you can use to explain how resources affect Earth.

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KEY TAKEAWAY

Think of Earth's systems like a game of dominoes. When you knock over one domino (like burning fossil fuels), it bumps the next one (more CO₂ in the air), which bumps another (warmer temperatures), and so on. To figure out which domino started the chain, you need evidence — real measurements and data that show the cause-and-effect links.

SECTION 3

How Resource Consumption Connects to Earth's Systems

The diagram below shows how human resource consumption sends ripple effects through all four of Earth's spheres. Follow the arrows to see how burning fossil fuels, mining, and deforestation create changes in the atmosphere, hydrosphere, geosphere, and biosphere.

This diagram shows three major categories of resource consumption (orange and red boxes at top) and how they send effects into all four Earth systems (colored boxes in the middle). The dashed lines show indirect connections, such as deforestation releasing stored carbon into the atmosphere.

Notice how the arrows crisscross. Burning fossil fuels mainly affects the atmosphere, but it also changes the hydrosphere through acid rain. Mining changes the geosphere, but runoff pollutes the hydrosphere too. This tells us something important: Earth's systems are connected, so changing one system often changes others. This is the crosscutting concept of Systems and System Models — scientists use diagrams like this one to model how parts of a system interact.

SECTION 4

How Fossil Fuel Consumption Changes the Atmosphere

The best-studied example of resource consumption affecting an Earth system is the link between fossil fuels and the greenhouse effect (the way certain gases in the atmosphere trap heat from the Sun). Here is how the mechanism works step by step.

Step-by-Step: Fossil Fuels and the Greenhouse Effect

Step 1 — Combustion: We burn coal, oil, or natural gas for energy. This chemical reaction releases carbon dioxide (CO₂) and water vapor into the atmosphere.
Step 2 — CO₂ Accumulates: CO₂ stays in the atmosphere for hundreds of years. Over time, the concentration (amount per volume of air) increases.
Step 3 — More Heat Is Trapped: CO₂ absorbs infrared radiation (heat energy) that Earth's surface sends upward. Instead of escaping to space, the heat stays near Earth.
Step 4 — Global Temperature Rises: With more heat trapped, Earth's average temperature slowly increases. This is the pattern scientists call global warming.

SIMPLIFIED COMBUSTION OF A FOSSIL FUEL (METHANE)

CH₄ + 2 O₂ → CO₂ + 2 H₂O + energy

CH₄ = methane (a fossil fuel found in natural gas). O₂ = oxygen from the air. CO₂ = carbon dioxide (the greenhouse gas). H₂O = water. Notice that CO₂ is always a product — you cannot burn a fossil fuel without creating it.

The crosscutting concept at work here is Cause and Effect. The cause is burning fossil fuels. The effect is rising CO₂ and rising temperatures. Scientists know this link is real because they can measure both the CO₂ increase and the temperature increase over the same time period.

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NGSS Connection

Science and Engineering Practice: Constructing Explanations. When you use the combustion equation and temperature data to explain why Earth is warming, you are doing exactly what scientists do — building an explanation from evidence.

SECTION 5

Reading the Evidence: Data That Tells the Story

Scientists use many types of evidence to show how resource consumption affects Earth. Let's look at the most important data sets. The graph below shows two key measurements plotted together: atmospheric CO₂ concentration and global average temperature change since 1880.

The red solid line shows atmospheric CO₂ concentration in parts per million (ppm). The dashed cyan line shows global average temperature change in degrees Celsius compared to the 1880 baseline. Both lines rise sharply after 1950, showing a clear pattern — as CO₂ goes up, temperature goes up.

What Patterns Do You See?

The crosscutting concept of Patterns is key here. Both lines on the graph trend upward over time. They also accelerate (get steeper) after about 1950. This is not a coincidence. After World War II, global energy use surged as more countries built factories, cars, and power plants. The data shows a clear correlation (two things changing together in the same direction).

Type of Evidence	What It Shows	Earth System Affected
Ice cores from Antarctica	CO₂ levels over 800,000 years; today's level is the highest ever recorded	Atmosphere
Ocean pH measurements	Oceans are about 30% more acidic than in 1800, because CO₂ dissolves into seawater	Hydrosphere
Satellite images of forests	Amazon rainforest has lost about 17% of its area in the last 50 years due to logging and farming	Biosphere & Geosphere
Sea-level tide gauges	Global sea level has risen about 20 cm since 1900 as ice melts and water expands from warmth	Hydrosphere
Mining site soil tests	Soil near mines has elevated levels of heavy metals like lead and mercury, harming plant growth	Geosphere & Biosphere

Examples of scientific evidence linking resource consumption to Earth system changes

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KEY TAKEAWAY

Imagine you notice your fish tank getting cloudier every day. You also notice you have been adding extra food. The pattern of cloudiness matching the extra food is evidence that overfeeding is the cause. Scientists do the same thing with Earth: they compare graphs of resource use and system changes to find matching patterns.

SECTION 6

Worked Example: Building an Evidence-Based Explanation

Let's practice the science and engineering practice of Constructing Explanations from Evidence. We will use a claim-evidence-reasoning (CER) framework. This is exactly how scientists present their findings.

Explain how burning fossil fuels has changed Earth's atmosphere

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Step 1 — State Your Claim

A claim is a statement that answers a question. Our claim: Burning fossil fuels has increased CO₂ in Earth's atmosphere, which has caused the average global temperature to rise.
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Step 2 — Present Your Evidence

Evidence is the data that supports your claim. Evidence 1: The Keeling Curve shows atmospheric CO₂ rose from about 315 ppm in 1958 to over 420 ppm in 2023. Evidence 2: NASA temperature records show Earth's average surface temperature has risen about 1.1 °C since the late 1800s. Evidence 3: Ice core data confirms CO₂ was stable near 280 ppm for thousands of years before industrialization.

Three pieces of evidence presented: Keeling Curve, NASA temperature record, and ice core data.
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Step 3 — Write Your Reasoning

Reasoning connects your evidence to your claim using scientific ideas. CO₂ is a greenhouse gas. It absorbs heat that would otherwise leave Earth. When humans burn fossil fuels, the chemical reaction produces CO₂ as a product. The pattern in the data — both CO₂ and temperature rising together after industrialization — shows a cause-and-effect relationship. This supports the claim that fossil fuel combustion is driving atmospheric change.

Complete CER: Claim states the connection. Evidence gives the data. Reasoning uses science to link them.

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Pro Tip

When writing your own CER, always ask: "Does my reasoning explain why my evidence supports my claim?" If you just list facts without explaining the science behind them, your reasoning is missing.

SECTION 7

Trade-Offs: Benefits and Costs of Resource Use

Resources are not all bad. They give us electricity, transportation, and materials for building. The challenge is that every resource comes with trade-offs (benefits you gain versus costs you pay). Understanding trade-offs helps communities make better decisions.

Resource	Benefits to Society	Costs to Earth Systems
Coal	Inexpensive electricity; abundant supply; supports jobs in mining regions	Highest CO₂ per unit of energy; acid rain from sulfur dioxide; mountaintop removal destroys land
Natural Gas	Cleaner-burning than coal; heats homes; supports cooking and manufacturing	Still releases CO₂; methane leaks are a potent greenhouse gas; fracking can contaminate groundwater
Forests (timber)	Building material; paper products; provides income for communities	Deforestation removes CO₂ absorbers; causes soil erosion; destroys habitat for wildlife
Solar Energy	No greenhouse gas emissions during use; renewable; dropping costs	Manufacturing panels uses energy and minerals; large solar farms require land; panels have a limited lifespan and need recycling
Fresh Water	Essential for drinking, farming, and industry; supports all life	Over-pumping lowers water tables; irrigation can cause soil salinization; diverting rivers harms ecosystems

Trade-offs associated with common resources

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KEY TAKEAWAY

Choosing a resource is like picking a meal deal at a restaurant. Every option has upsides (taste, nutrition) and downsides (cost, calories). The crosscutting concept of Stability and Change reminds us that some choices keep Earth's systems stable while others push them toward unwanted change. Using evidence about trade-offs helps us pick the best option.

SECTION 8

From Middle School to High School: Where This Leads

The ideas you are learning now form the foundation for more advanced science. In high school, you will use quantitative models (equations with real numbers) to predict how much warming a certain amount of CO₂ will cause. You will also study feedback loops — cycles where an effect makes the original cause stronger or weaker.

What You Learn Now (MS)	What Comes Next (HS)
Identify evidence that CO₂ is rising	Calculate carbon budgets and emission rates using algebra
Describe how burning fossil fuels warms Earth	Model the greenhouse effect using energy balance equations
Compare renewable and nonrenewable resources	Evaluate life-cycle analysis of energy sources (cradle-to-grave costs)
Use CER to explain a single Earth system change	Use computational models to predict multi-system impacts decades into the future

How these concepts build toward high school Earth science

The skills you practice now — reading graphs, finding patterns, and writing evidence-based explanations — are the same skills climate scientists use every day. You are building real scientific thinking.

SECTION 9

Practice Problems

Question 1: CONCEPTUAL

Which of the following is the best definition of a nonrenewable resource? A. A resource that can never be used by humans B. A resource that takes millions of years to form and is used faster than it is replaced C. A resource that comes only from the ocean D. A resource that is always harmful to the environment

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B. A nonrenewable resource takes millions of years to form and is consumed faster than nature replaces it. Option A is wrong because nonrenewable resources can be used — that is the problem; we use them up. Option C is wrong because many nonrenewable resources (like coal) come from land. Option D is wrong because the resource itself is not automatically harmful; it is how we extract and use it that causes effects on Earth systems.

Question 2: BASIC CALCULATION

In 1960, atmospheric CO₂ was about 317 ppm. In 2020, it was about 414 ppm. What was the total increase in CO₂ over those 60 years? A. 97 ppm B. 731 ppm C. 317 ppm D. 60 ppm

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A. Subtract the earlier value from the later value: 414 − 317 = 97 ppm. Option B is wrong because it adds the two values instead of subtracting. Option C just restates the 1960 value. Option D uses the number of years, not the CO₂ change. This problem shows how scientists use quantitative evidence (numbers and measurements) to track changes in Earth systems.

Question 3: INTERMEDIATE

A student looks at a graph and notices that global fossil fuel use and ocean acidity both increased between 1950 and 2020. The student claims: "Burning fossil fuels caused the ocean to become more acidic." Which piece of reasoning best supports this claim? A. Fossil fuels are found underground, and the ocean is above ground, so they cannot be connected. B. CO₂ released by burning fossil fuels dissolves into ocean water, forming carbonic acid, which lowers pH. C. The ocean has always been acidic, so fossil fuels do not matter. D. Fossil fuel use went up, so everything else must also go up at the same time.

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B. This option provides the scientific mechanism — CO₂ dissolves in seawater and creates carbonic acid, which lowers the pH. This is proper reasoning in a CER response. Option A incorrectly assumes underground and above-ground systems are unconnected (they share the atmosphere). Option C is factually incorrect; the ocean was less acidic before industrialization. Option D confuses correlation with a blanket rule — not everything rises just because fossil fuel use does. Good reasoning must explain the cause-and-effect mechanism.

Question 4: APPLIED

A town decides to replace its coal power plant with a solar farm. A citizen argues: "Solar energy has zero impact on Earth's systems." Using what you know about trade-offs, which response best evaluates this claim? A. The citizen is completely correct — solar energy is perfectly harmless. B. Solar panels produce no greenhouse gases during use, but manufacturing panels requires mining minerals and using energy, which do affect Earth systems. The overall impact is much smaller than coal. C. Solar farms are worse than coal because they take up more land. D. Since solar energy comes from the Sun, it cannot affect any part of Earth.

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B. This answer correctly applies the idea of trade-offs. Solar energy produces no CO₂ during use, but making panels still requires resources and energy. Option A ignores the manufacturing impacts. Option C is misleading because land use alone does not make solar worse; coal's atmospheric damage is far greater. Option D incorrectly claims that an energy source from the Sun cannot have any effect on Earth. Every resource has some cost — the key is that solar's costs are much smaller than coal's.

Question 5: CRITICAL THINKING

Two students are debating. Student A says: "CO₂ and temperature rose at the same time, so CO₂ must cause warming." Student B says: "Just because two things happen together does not prove one causes the other." Who is making a stronger scientific argument, and what additional evidence would settle the debate? A. Student A is correct; matching graphs always prove cause and effect. B. Student B is correct; matching graphs can never support cause and effect. C. Student B raises a fair point about correlation, but laboratory experiments show CO₂ absorbs infrared radiation, and climate models accurately predict warming based on CO₂ levels. Together, the mechanism and the data pattern strongly support cause and effect. D. Neither student is making a scientific argument because they are not conducting an experiment.

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C. Student B correctly points out that correlation alone does not prove causation — this is an important scientific principle. However, Student B goes too far if they reject the connection entirely. Lab experiments confirm that CO₂ traps heat (the mechanism), and climate models using CO₂ data accurately predict observed warming (the test of the model). When you combine the pattern in data with a tested mechanism, you have strong support for cause and effect. Option A is wrong because matching graphs alone are not proof. Option B is wrong because patterns plus mechanisms can support causation. Option D is wrong because analyzing data and constructing explanations are legitimate scientific practices even without a new experiment.

SUMMARY

Lesson Summary

Summary

Human resource consumption — especially burning fossil fuels, mining, and deforestation — sends ripple effects through Earth's atmosphere, hydrosphere, geosphere, and biosphere. The greenhouse effect explains why adding CO₂ to the atmosphere traps more heat and raises global temperatures. Scientists use evidence like the Keeling Curve, ice cores, and ocean pH data to show these cause-and-effect relationships.

Every resource involves trade-offs between benefits to society and costs to Earth systems. Using a Claim-Evidence-Reasoning (CER) framework, you can construct scientific explanations that connect data (patterns) to mechanisms. By identifying renewable alternatives and understanding nonrenewable limits, you can evaluate solutions that promote stability in Earth's interconnected systems.