Carbon Dioxide

Carbon dioxide is a gas you cannot see or smell. It is made of carbon and oxygen atoms joined together. People and animals breathe it out after using oxygen in their bodies. Plants take in carbon dioxide to help them grow. It is an important part of the air around us.

How Plants Use It

Plants need carbon dioxide to live and grow. They take it in through tiny holes in their leaves. Using sunlight and water, they turn it into food and give off oxygen. This process is called photosynthesis. Without carbon dioxide, plants could not make food for themselves or for animals.

Carbon Dioxide and Earth

Carbon dioxide helps keep Earth warm enough for life. It traps some heat from the sun in our atmosphere. But too much of it can make the planet warmer than normal. People make extra carbon dioxide when they burn gas, coal, and oil. Scientists study this gas to help protect our planet.

Fun Facts

• Carbon dioxide makes the bubbles in soda and sparkling water.
• Dry ice is frozen carbon dioxide and is very cold.
• The air we breathe out has about 100 times more carbon dioxide than the air we breathe in.

Did You Know?

Firefighters sometimes use carbon dioxide to put out fires because it pushes oxygen away from the flames.