I think what is soviet union or germany
Scientists believe that increased pollution may cause global warming because pollution includes greenhouse gases, which trap heat in the Earth’s atmosphere.
Option B
<u>Explanation</u>:
When the average temperature of earth increases and rises continuously above the normal value for a long period of time the it is referred as global warming.
Human beings are major cause in increasing pollution by various means whether its chemical industrial metallic or any other type of pollution. The major contributing factor in aiding pollution is the smoke from factories or vehicles which increases the carbon dioxide level above normal and when these gases rises they are trapped inside the earth surface and produce a green house effect. This is the main reason that scientists think aboutglobal warming.
People migrate to the new lands, populate, build cities, created businesses, trade, settle.
