What are the main causes of rising ocean levels?

The significant increase in the release of greenhouse gases such as carbon dioxide into the atmosphere leads to major issues such as :-

1- Global warming:

Adding greenhouse gases has little effect on incoming short-wave solar radiation, but increases the amount of outgoing long-wave terrestrial radiation that is absorbed in the lower atmosphere. The result is warming of the lower atmosphere (commonly known as the enhanced greenhouse effect, or global warming). Potentially, there are other effects on our climate also – changes in rainfall distribution and storminess, for example.

2- Rise in ocean levels:

Adding greenhouse gases has little effect on incoming short-wave solar radiation, but increases the amount of outgoing long-wave terrestrial radiation that is absorbed in the lower atmosphere. The result is warming of the lower atmosphere (commonly known as the enhanced greenhouse effect, or global warming). Potentially, there are other effects on our climate also – changes in rainfall distribution and storminess, for example.

· Other causes:

1- Thermal expansion :-

· When water heats up, it expands. About half of the sea-level rise over the past 25 years is attributable to warmer oceans simply occupying more space.

2- Melting Glaciers :-

· Large ice formations such as mountain glaciers naturally melt a bit each summer. In the winter, snows, primarily from evaporated seawater, are generally sufficient to balance out the melting. Recently, though, persistently higher temperatures caused by global warming have led to greater-than-average summer melting as well as diminished snowfall due to later winters and earlier springs. That creates an imbalance between runoff and ocean evaporation, causing sea levels to rise.

3- Loss of Greenland and Antarctica’s ice sheets:-

As with mountain glaciers, increased heat is causing the massive ice sheets that cover Greenland and Antarctica to melt more quickly. Scientists also believe that melt water from above and seawater from below is seeping beneath Greenland's ice sheets, effectively lubricating ice streams and causing them to move more quickly into the sea. While melting in west Antarctica has drawn considerable focus from scientists, especially with the 2017 break in the Larsen C ice shelf, glaciers in East Antarctica are also showing signs of destabilizing.