Global warming is a direct causal factor of intense melting of polar ice caps in the earth. The increase of atmospheric temperature and ocean temperature enhances melting of ice in Arctic glaciers and Greenland ice. This melting adds significant amounts of freshwater to the oceans directly raising worldwide seas.
The Antarctic ice sheet is unstable as well. Melting of ice shelves is caused by warming of oceans. This melting undermines the shields against huge blocks of glaciers on land so that the ice melts and enters the sea and this process further increases sea levels.
Due to the increasing temperature of the ocean, thermal expansion of the seawater contributes a big volume to the ocean. This process together with the addition of the meltwater to the polar ice caps land is the major cause of the rising mean sea levels world over.
As a result, coastal areas all over the globe are also under threat of rising sea levels. The direct impacts include increased inundation, coastal erosion, and encroachment of salty waters into aquifers of freshwater. Especially hard hit are the low-lying territories and the island countries.
The process is quantifiable and gaining pace. The melting glaciers in polar regions and its resultant thermal expansion assure at least further rise in sea level over several centuries, which poses a big global challenge and needs to be curbed with a sense of urgency.
Conclusion :
There is no doubt that global warming causes thermal expansion and the melting of the polar ice caps and hence the increase in sea levels. Direct contributors to this increase are the faster melting of the ice in Greenland, the arctic, and Antarctica. The direct outcomes are coastal inundation, erosion and salt water intrusion. Reduction of future warming is necessary to reduce the amount of long-term sea-level rise and its extreme effects.
