ReadWorks Is the Earth Getting Warmer?

What is a feedback loop?

A feedback loop is a process that helps to amplify or diminish certain changes within the process.

How can heat produce more heat? Use information from the passage to support your answer.

Answers may vary and should be supported by the passage. Students should indicate that heat produces more heat in positive feedback loop systems. Students may also illustrate this phenomenon using one of the examples from the passage. For example, they may mention the example of melting permafrost. Some of the gases that contribute to global warming are trapped in permafrost. When permafrost melts, many of these gases are released into the atmosphere. This leads to an increase in the atmosphere's temperature, which causes more permafrost to melt. As more permafrost melts, the atmosphere's temperature increases. Thus, heat can produce more heat.

Arctic ice plays an important role in cooling the Earth. Which evidence from the passage best supports this statement?

Arctic ice reflects the Sun's light.

How does carbon dioxide increase the Earth's temperature?

Carbon dioxide traps heat which can cause the Earth's temperature to rise if large quantities of carbon dioxide are released in the Earth's atmosphere.

What is the main idea of this passage?

Climate change is a complex and unpredictable process involving feedback loops.

The increase of carbon dioxide in the atmosphere has had which effect on the Earth's climate?

The Earth's temperatures are rising.

According to the passage, which gas is generated in especially large amounts when we burn fossil fuels?

carbon dioxide

Read the following sentences: "Some scientists expect an increase in so-called 'extreme weather' events, such as hurricane and floods. Others foresee a rise in levels of sea water." Which word could best replace "foresee" as used in this sentence?

forecast

Choose the answer that best completes the sentence below. Trees play important roles in preventing global warming, _________ absorbing carbon dioxide and pumping water into the atmosphere.

including

Some of the gases that contribute to global warming are trapped in permafrost. When permafrost melts, many of these gases are released into the atmosphere. This leads to an increase of the atmosphere's temperature, which causes more permafrost to melt. What type of feedback loop is this an example of?

positive feedback loop