Question

what are harmful effects of global warming

Answer 1

The short, global climate change (global warming) is real. I want to explain below the difference between "natural processes" and "human influence" to give you a better picture of why global warming is so important. Here's my long version below: 

Over the geologic timescale, the Earth has gone through natural variations in the amount of carbon dioxide. The long-term inorganic carbon-silicate weathering cycle accounts for these discrepancies. First, carbon dioxide is dissolved in rainwater which reacts to form carbonic acid. From there, the rainwater falls on land or ocean. On land, carbonic acid reacts with rocks and combines to form a bicarbonate ion through the process of weathering. These weathered carbonate materials are then carried to the ocean and form minerals on the ocean floor. The rocks that form the ocean floor are gradually carried toward the continental boundaries by plate tectonics, where the carbonate rock is subducted under the continental crust. The rock is then heated as it descends into the mantle, releasing the carbon dioxide and allowing it to escape and return to the atmosphere through volcanic eruptions. This ongoing cycle regulates the carbon dioxide content of the Earth’s atmosphere and acts as a thermostat to keep the Earth’s climate fairly stable. The cycle also ensures that most of the Earth’s carbon dioxide resides in carbonate minerals on the ocean floor rather than in the atmosphere as carbon dioxide gas. 

Answer 2

EFFECTS OF GLOBAL WARMING ARE AS FOLLOWS :

=> An increase of as less 1°C in Earth's temperature can lead to melting of polar ice caps and consequent rise in sea level. A rise in sea level can submerge a number of major cities of the world, which are located along the sea coasts. Besides causing the floods in low-lying coastal cities, global warming poses a threat of recurrence of dust bowl condition of 1930's. Dust bowl is an area where vegetation has been lost and soil reduced to dust making it susceptible to erosion.

=> Increase in temperature of the Earth due to green house effect will cause a change in weather and precipitation patterns on the Earth.

=> One of the danger of continued global warming is methane burp whch is caused by the melting of the methane hydrates in permafrost (of polar ice) and on the sea floor. Methane being a green house gad increases global warming.