LEAP 2025 ELA Grade 8 Post Test

LEAP 2025 ELA Grade 8 Post Test Sample

The Greenhouse Effect

1 The greenhouse effect is when the Earth’s atmosphere traps solar radiation caused by gases such as carbon dioxide, water vapor, and methane. These gases allow incoming sunlight to pass through but absorb heat radiated back from the Earth’s surface. National Aeronautics and Space Administration (NASA) scientists state that the gases that contribute to the greenhouse effect include:

2 Water vapor – It is the most plentiful greenhouse gas, and as water vapor increases as the Earth’s atmosphere warms, it creates clouds and precipitation.

3 Carbon dioxide (CO2) –Carbon dioxide is released through natural processes like volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased atmospheric CO2 concentration by a third since the Industrial Revolution began.

4 Methane – This is a gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and domestic livestock.

5 Nitrous oxide –This is a powerful greenhouse gas produced by commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning, which is the burning of living and dead vegetation.

6 Chlorofluorocarbons (CFCs) –They are a group of manufactured chemical compounds, such as aerosol sprays, refrigerators, and fire extinguishers that contain chlorine, fluorine, and carbon. CFCs are also a greenhouse gas because they absorb heat in the atmosphere, sending some of the absorbed heat back to the surface of the Earth and contributing to global warming and climate change.

The Human Problem

7 Scientists agree that humans have greatly contributed to the greenhouse effect. Over the last century, the burning of fossil fuels like coal and oil has increased the amount of carbon dioxide in the atmosphere. Clearing land for agricultural purposes and industry have also increased concentrations of greenhouse gases.

The Industrial Revolution and Its Impact on Our Environment

8 The Industrial Revolution began in England in the 1700′s when machinery began to replace manual labor. And this revolution quickly spread to the rest of the world, beginning with the United States. Industry needed a more efficient energy source to replace wind, water, and wood that were used in the past. This led to the burning of fossil fuels which were used primarily for the manufacture of textiles and the development of iron making processes. The effects on the environment would not be known until many years later.

9 The Industrial Revolution led to increases in production capacity and would affect all basic human needs, including food production, medicine, housing, and clothing. Unfortunately, factories and mass production led to a depletion of certain natural resources, leaving the environment permanently damaged. One example of this depletion is deforestation, which is the clearing of forest trees for use in production.

10 The lack of trees created problems with carbon emissions. Abundant forests help give off oxygen and refresh the levels of healthy gases in the air. But factories emitted poisonous emissions and eliminated the healthy source of oxygen. The depletion of natural resources, carbon emissions, and pollution that resulted from the Industrial Revolution’s accomplishments in industry have been disastrous for Earth’s environment.

11 The Environmental Protection Agency (EPA) tracks total U.S. emissions and publishes its findings in the Inventory of U.S. Greenhouse Gases and Sinks. The EPA reports that the primary sources of greenhouse gas emissions in the United States are:

12 Electricity Production - Electricity production generates thirty-two percent of greenhouse gas emissions. Over seventy percent of our electricity comes from burning fossil fuels, mostly coal and natural gas.

13 Transportation - Twenty-eight percent of greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over ninety percent of the fuel used for transportation is petroleum based, which includes gasoline and diesel.

14 Industry – Twenty percent of greenhouse gas emissions result from burning fossil fuels for energy, as well as greenhouse gas emissions from certain chemical reactions necessary to produce goods from raw materials.

15 Commercial and Residential – Ten percent of greenhouse gas emissions from businesses and homes arise primarily from fossil fuels burned for heat, the use of certain products that contain greenhouse gases, and the handling of waste.

16 Agriculture - Nine percent of greenhouse gas emissions from agriculture come from livestock such as cows, agricultural soils, and rice production.

17 Land Use and Forestry - Fifteen percent of greenhouse gases come from land use and forestry. Land areas can act as a sink by absorbing more carbon dioxide from the atmosphere than they emit.

18 NASA scientists who study the harmful effects of greenhouse gases say that the consequences of the greenhouse effect are difficult to predict, but that most likely:

  • The Earth will become warmer. Some regions may welcome warmer temperatures, but others may not.
  • Warmer conditions will probably cause some regions to become wetter, and other regions will become dryer.
  • The greenhouse effect will warm the oceans and partially melt glaciers and other ice, causing sea levels to rise.
  • Higher temperatures and shifting climate patterns may change the areas where crops grow best and affect natural plant communities.

19 No one is sure if the greenhouse effect can be completely reversed, but to help ensure man’s survival well into the future, scientists say that Earth’s atmosphere can become cleaner by recycling and using biomass energy, wind energy, solar energy, geothermal energy, and hydroelectric energy as alternative energy sources.

1 pt
1a.

What is the central idea of this passage?

1 pt
1b .

Which sentence from the passage supports the answer to Part A?

1 pt
2a.

How does this passage make the connection between the Industrial Revolution and the greenhouse effect?

1 pt
2b.

The Industrial Revolution led to the destruction of Earth’s atmosphere by –

1 pt
3a.

What is the author’s point of view regarding the greenhouse effect?