The immediate impact of global warming are rapid melting of ice in the Polar Regions and mountain glaciers. Melting of the polar ice caps in the Artic and Antarctic will lead to rise in sea levels across the world.
This will bring many coastal cities under water and also contaminate fresh water sources. Melting of ice in the mountain glaciers will initially lead to the river being fed by these glaciers to flood. When all the ice melt, the same river will dry up leaving us with little or no fresh water.