The Earth's temperature - Higher
The temperature of a body is linked to the balance between the amounts of radiation absorbed and emitted.
| Rate of absorption | Temperature of the body |
| Greater than the rate of emission | Increasing |
| Equal to the rate of emission | Constant |
| Less than the rate of emission | Decreasing |
| Rate of absorption | Greater than the rate of emission |
|---|---|
| Temperature of the body | Increasing |
| Rate of absorption | Equal to the rate of emission |
|---|---|
| Temperature of the body | Constant |
| Rate of absorption | Less than the rate of emission |
|---|---|
| Temperature of the body | Decreasing |
Factors affecting the Earth鈥檚 temperature
The temperature of the Earth depends on many factors including the concentration of greenhouse gases such as:
- When water exists in the form of a gas. Steam is water vapour.
- A colourless gas that can do harm to life forms.
- A gaseous compound of carbon and oxygen, which is a by-product of respiration, and which is needed by plants for photosynthesis.
The Earth鈥檚 temperature also depends on the rates at which light radiation and Electromagnetic radiation with a wavelength longer than visible light. are absorbed and emitted by the Earth鈥檚 surface and atmosphere.
The effect of Earth's atmosphere on its temperature
- When visible light and high frequency infrared radiation are absorbed by the surface of the Earth, the surface gets hotter.
- The Earth also radiates lower frequency infrared radiation. Some of this infrared radiation is transmitted through the atmosphere back out into space, and some is absorbed by greenhouse gases in the atmosphere.
- The greenhouse gases emit infrared radiation in all directions 鈥 some out into space and some back towards Earth, which is then reabsorbed.
The greenhouse effect
The 鈥榞reenhouse effect鈥 caused by naturally occurring greenhouse gases, such as water vapour, stabilises the surface temperature of Earth. This allows the planet to support life.
However, human activities such as deforestation and the burning of fossil fuels are releasing additional carbon dioxide. This causes more infrared radiation to be 鈥榯rapped鈥 and reabsorbed by the Earth鈥檚 surface. This enhanced greenhouse effect is causing global temperatures to increase, leading to The long-term alteration of weather patterns..