Summary

This video begins by explaining  how carbon dioxide (CO₂) gets into our atmosphere, including the roles of photosynthesis and greenhouse gases in the carbon cycle. The video then explains why fossil fuels add CO₂ to the atmosphere. Plants help us balance that output of CO₂ because they take in CO₂ to make food, but we still need to be careful not to overload the system.

Why watch this video?

• Have you ever wondered how CO₂ gets into our atmosphere?
• Would you like to know how the carbon cycle works?
• Have you ever been confused by the role that fossil fuels play in the carbon cycle?

Key terms

Photosynthesis: a process where plants and some organisms use sunlight to break down carbon dioxide (CO₂) and release oxygen as a byproduct.

Fossil fuels: natural fuels like coal or gas that are formed from the remains of living organisms.

Greenhouse gases: a gas that contributes to the ‘greenhouse effect’ by absorbing radiation, such as CO₂.

Loose ends

• Carbon dioxide affects climate because it traps heat energy in the atmosphere.
• Greenhouse gases can be released by natural processes or by human activities. Carbon dioxide is one type of greenhouse gas, but there are others such as methane (CH₄; released by nature and human activities) and chlorofluorocarbons (CFCs, made only by humans).
• People cause climate change by adding greenhouse gases to the atmosphere, and that means they can do something about climate change by reducing or stopping the release of greenhouse gases. There are many reliable and affordable alternative energy sources that can be used to replace those that release greenhouse gases into the atmosphere, but people must put pressure on governments to make the necessary changes to support the use of these alternatives.

Self-Test Questions