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What Causes Global Warming? — Reading Comprehension

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This NGSS-aligned reading passage explains what causes global warming, focusing on how human activities like burning fossil fuels, deforestation, and farming release greenhouse gases. Students will learn how carbon dioxide, methane, and nitrous oxide trap heat in Earth’s atmosphere, leading to rising temperatures. With clear examples and vocabulary support, this passage is ideal for building reading comprehension and science literacy in middle school students. It supports NGSS Earth and environmental science standards with activities that encourage critical thinking and real-world connections.

CONTENT PREVIEW

Global warming is the long-term rise in Earth’s average temperature. It is mostly caused by human activities that release gases into the atmosphere. These gases trap heat and make the planet warmer. The biggest cause of global warming is the increase in greenhouse gases like carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O).

The most common source of these gases is the burning of fossil fuels. Fossil fuels include coal, oil, and natural gas. People burn these fuels to make electricity, power cars and trucks, and run factories. When fossil fuels burn, they release large amounts of carbon dioxide into the air.

Another major cause is deforestation, or cutting down forests. Trees naturally absorb carbon dioxide from the air. When forests are cleared for farming or building, fewer trees are left to clean the air. In addition, when trees are burned or rot, they release stored carbon into the atmosphere.

Farming also adds to global warming. Animals like cows produce methane during digestion, and some fertilizers used on crops release nitrous oxide. These gases are stronger than carbon dioxide and trap even more heat.

Waste from landfills can release methane as food and other materials break down. Even everyday items like air conditioners and refrigerators can leak gases that warm the planet.

Together, these human actions have added too many greenhouse gases to the air. As a result, Earth’s natural balance is changing, and the planet is getting warmer.

Fun Fact: Methane traps about 25 times more heat than carbon dioxide over 100 years!

What is the main cause of global warming?

VolcanoesHuman activities that release greenhouse gasesEarth’s natural cycleToo much sunlight

What are greenhouse gases?

Gases used in farmingGases that help plants growGases that trap heat in the atmosphereGases found only in outer space

Which gas is mostly released when fossil fuels burn?

OxygenCarbon dioxide (CO₂)HeliumNitrogen

What is deforestation?

Planting new treesClearing forests by cutting down treesCleaning up forestsBuilding treehouses

Why does cutting down trees add to global warming?

Trees block sunlightTrees cool the planetTrees release oxygenFewer trees means less CO₂ is removed from the air

What farm animals produce methane?

HorsesPigsChickensCows

What is the main idea of the passage?

Trees make too much CO₂Global warming is caused mostly by human activitiesAnimals are the main reason for warmingAir conditioners are good for the climate

What is one way waste contributes to global warming?

It cools the airIt reduces rainfallLandfills release methane gasTrash turns into fertilizer