NOVA Decoding the Weather Machine IL
Choosing Earth's Climate Future

Reducing the Amount of CO2 in the Atmosphere

Even if carbon dioxide (CO2) emissions stopped completely tomorrow, the climate would continue to change. That is because there is already so much CO2 in the atmosphere. To stop or reduce the rate of global climate change requires negative emissions. Negative emissions mean taking more carbon out of the atmosphere than is released into the atmosphere. 

On a global scale, achieving negative emissions requires technologies that can pull CO2 from the air and store it safely underground—a process known as carbon capture. Carbon capture may sound impossible, but it is not. Plants do it all the time!

Read the following passage about photosynthesis. Then, click on Match It below to review how plants help cycle carbon. Before moving to the next page, respond to the prompt in the Take Notes section.
While they are growing, plants take in and store more carbon dioxide than they release.
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Photosynthesis
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Plants use a process called photosynthesis to generate carbon-containing sugars from carbon dioxide (CO2) that they pull from the air. Most of these sugars are either stored or get turned into other molecules that make up the plant itself. When the plant dies and breaks down, the carbon it contained is added to the soil. 

Plants, like all living things, release some CO2 through respiration. Respiration is the process of using oxygen (O2) to break down sugars to obtain energy and release CO2. Decomposers also release some CO2 as they break down dead plant matter. However, plants take in much more CO2 than they release, which makes them an important part of the plan to capture carbon and fight climate change.

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View in My Work

Plants take in carbon dioxide from the atmosphere and use it during  photosynthesis to produce and store sugars.

When plants die and decay, the carbon they contain is released to the soil.

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Take Notes

  • Based on your understanding of the process of carbon capture involving plants, describe at least one way that human activities can decrease the effectiveness of the process.