Global warming has been identified as a major issue for the global community. More properly this is called "Global Climate Change" as some areas may be warmer, some cooler, some wetter, some drier...
Background: The contention of the larger number of climatologists is that human activities since the industrial revolution have increased the content of CO
2, methane, and other gases in the atmosphere that trap solar heat. At the same time human activities have reduced the forest cover that had traditionally absorbed these same materials. They state that an increasing level of these atmospheric constituents has lead to a chain of chemical and physical changes that have increased the world's average temperature.
Observations of atmospheric gas composition, average sea water temperatures, atmospheric temperatures etc. confirm the trends and support the proposition.
Potential Impacts:1. The sea levels may rise. Technically this may be caused by melting ice from the polar ice caps or an increase in sea height as the less dense water is less compressed. Low lying land like many Pacific Islands and Miami will be under water.
2. Serious climate changes may result from diverted ocean currents. As an example, the Gulf Stream keeps Europe warm. If the Stream is not running Europe may be much cooler and drier. Crops may not grow.
3. Ecology changes on the land could include species of animals and plants extending their range to the polar regions. Local flora and fauna may become extinct. A good example is the spread of Africanized bees and Fire Ants. Sea life may also be impacted both through the introduction of competitive species presently kept in other areas by water temperature changes, and by failure to adapt to less saline water.
4. Human society may be disrupted if changes in rainfall and temperature cause crop failure. Famine refugees may require significant humanitarian attention by the "lucky" nations.
There are several disadvantages to Global Warming, which will affect all life on this planet. As the Earth warms, the ocean levels will rise due to melting ice in Greenland, and the Antarctic, with an additional rise due to thermal expansion (warm water takes up more space than cold water). The rising ocean levels will innundate roads, farmland, towns, and even cities. The economic cost will be in the trillions. A warmer Earth equals more powerful storms, with increasing frequency. Wildlife will suffer if their habitats change more quickly than they can adapt. Global weather patterns will be altered as temperature differentials change planet-wide. These are a few of the disadvantages...and this is only "the tip of the iceberg", no pun intended.