Scaffolded notes
Build the idea
The natural greenhouse effect supports life
Incoming solar energy is mostly shortwave radiation. Earth absorbs part of it and emits infrared radiation. Greenhouse gases absorb and re-emit some infrared energy, slowing energy loss to space and keeping the lower atmosphere and surface warmer than they otherwise would be.
Composition affects energy balance
Increasing concentrations of carbon dioxide, methane, and other greenhouse gases increases the atmosphere's ability to absorb outgoing infrared energy. The climate system then warms until incoming and outgoing energy balance again, with responses in oceans, ice, water vapor, and clouds.
Use multiple lines of data
Scientists analyze atmospheric gas measurements, global surface temperatures, ocean heat, ice, satellites, and physical models. A graph can show correlation, while the tested radiation mechanism provides a cause-and-effect explanation.
Stop and explain
Check your thinking
1. Which radiation is strongly involved in the greenhouse effect?
Possible response: Outgoing infrared radiation from Earth.
2. Why use ocean heat data as well as surface temperature?
Possible response: The climate system stores energy in multiple components, especially oceans.
Interactive challenge
Try the science
Arrange the simplified greenhouse-energy pathway.
- Greenhouse gases absorb and re-emit some infrared energy
- Earth emits infrared radiation
- Surface absorbs energy and warms
- Sunlight reaches Earth
Before you leave
Exit ticket
Describe the greenhouse effect without using the phrase 'traps heat.'