Thermal layers refer to the different levels of temperature found in the atmosphere. As you move higher from the Earth's surface, the temperature can change significantly. For example, in the troposphere, which is the lowest layer, temperatures generally decrease with altitude. This is where most weather occurs, and it contains the air we breathe. Above the troposphere, the stratosphere is the next layer, where temperatures actually begin to rise with altitude due to the presence of the ozone layer. This layer absorbs harmful ultraviolet radiation from the sun, making it warmer higher up. Understanding thermal layers helps scientists predict weather patterns and study climate change.