1.3 Gases in the atmosphere absorb radiation.
The ozone layer protects life from harmful radiation. An ozone molecule is made of three oxygen atoms. The ozone layer protects life on Earth by absorbing harmful ultraviolet radiation from the Sun. Too much ultraviolet radiation can cause sunburn, skin cancer, and damaged eyesight. Ultraviolet radiation can harm crops and materials such as plastic or paint. Ozone absorbs ultraviolet radiation but lets other types of radiation, such as visible light, pass through.
The greenhouse effect keeps Earth warm.
Certain gases in the atmosphere slow the movement of energy (heat) away from Earth's surface. The gases absorb and emit infrared radiation, which keeps energy in Earth's surface. The gases absorb and emit infrared radiation, which keeps energy in Earth's system for a while. This process was named the greenhouse effect because it reminded scientists of the way glass traps warmth inside a greenhouse. Carbon dioxide, methane, water vapor, nitrous oxide, and other gases that absorb and give off infrared radiation are known as greenhouse gases.
1.4 Human activities affect the atmosphere.
Smoke and other harmful materials that are added to the air are called air pollution. Outdoors, wind can spread air pollution from place to place the way a fan does within your home.
Types of pollution:
Types of pollution:
- Particulates
- Fossil Fuels
Human activities are increasing greenhouse gases. Most greenhouse gases occur naturally. They have helped keep temperatures within a range suitable for the plants and animals that live on Earth. Human activities are also producing greenhouse gases faster than natural processes can remove these gases from the atmosphere.
Global Warming
Currently the levels of carbon dioxide in the air are the highest in the last 800,000 years.
Currently the levels of carbon dioxide in the air are the highest in the last 800,000 years.
- On average, Earth will become warmer. Some regions may welcome warmer temperatures, but others may not.
- Warmer conditions will probably lead to more evaporation and precipitation overall, but individual regions will vary, some becoming wetter and others dryer.
- A stronger greenhouse effect will warm the oceans and partially melt glaciers and other ice, increasing sea level. Ocean water also will expand if it warms, contributing further to sea level rise.
- Meanwhile, some crops and other plants may respond favorably to increased atmospheric CO2, growing more vigorously and using water more efficiently. At the same time, higher temperatures and shifting climate patterns may change the areas where crops grow best and affect the makeup of natural plant communities.