Atmosphere Definition

by Laurent Cousineau
(Montreal)

An atmosphere is a gaseous envelope that surrounds a material of sufficient mass and is held in place by gravity.

When discussing climate change or environmental issues, it is implicit that we are referring to the Earth’s atmosphere.

In our planet, about 78.1% of the dry atmosphere is made up of nitrogen and around 20.9% consists of oxygen.

The remaining 1% consists of trace gases such as argon (0.93%), helium, and several greenhouse gases including carbon dioxide (0.035%).

Moreover, the atmosphere also contains water vapour, clouds, and aerosols along with some particulate matter.

Main Layers

• Exosphere
• Thermosphere
• Mesosphere
• Stratosphere
• Troposphere

Other Layers

• Ozone Layer
• Ionosphere
• Homosphere and Heterosphere
• Planetary Boundary Layer

The Atmosphere and Climate Change

The Earth's atmosphere plays a pivotal role in climate change since it is where climate and weather take place.

In order to help stop climate change, we must reduce the amount of greenhouse gases we emit into the atmosphere.

By doing so, we will slow down the greenhouse effect which is responsible for global warming.