The concentrations of greenhouse gases present in the past have been evaluated using gas bubbles trapped in ice.
Greenhouse gases are those gases that trap heat coming from the sun and raise the overall temperature of the earth.
The most common greenhouse gases (GHGs) are carbon dioxide (CO2), methane (CH4), and water vapors which are responsible for global warming.
These gases are present naturally in the atmosphere whereas some artificial gases are also being released into the atmosphere such as fluorinated gases or HFCs.
These are synthetic in nature and have a harmful impact on the atmosphere.
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