Global warming is a natural phenomenon marked by a significant rise in the near-surface temperature of the Earth, largely due to various anthropogenic activities. Though there exist some natural causes for this rise in temperature, they stand to be insignificant when compared to anthropogenic causes.

Causes of Global Warming

Natural Causes
These include the release of methane, volcanic eruptions, etc. Methane is a greenhouse gas, notorious for its ability to trap the heat within the Earth's atmosphere. It is released in large quantities in the Arctic tundra and wetlands. In the event of a volcanic eruption, tons of ash is released into the atmosphere. As we can see, the nature does play a role in global warming, but it's too small compared to human contribution.

Anthropogenic Causes
These include a range of human activities, right from pollution to mining. When we talk about pollution, a large part of the same can be attributed to the burning of fossil fuels. When coal is burned to produce electricity or gasoline to power internal combustion engine, they let out carbon dioxide. Like methane, even carbon dioxide is one of the greenhouse gases, which trap heat within the Earth's atmosphere.

It's also worth noting that methane doesn't just escape into the atmosphere because of natural occurrences, but is also released in huge quantities as a result of mining―a human activity.

If we start analyzing these and other such anthropogenic causes, we zero in on population growth. More population means more requirements, which includes food, electricity, and transportation. In order to fulfill these requirements, more fossil fuels are consumed, and this, in turn, accelerates to global warming.

It's also worth noting that we humans release carbon dioxide as a bi-product of respiration. With an increasing population, the amount of carbon dioxide we breathe out also increases.

Even agriculture contributes to global warming, due to the extensive use of fertilizers and the dung produced by cattle, which is yet another prominent source of methane.

Effects of Global Warming

Changes in the Global Sea Level
With the global near-surface temperature rising, the ice cover on the planet has started melting. The water from these melting glaciers ends up in the oceans, which leads to a rise in the sea level. Over the last century, sea levels have increased by 4 - 8 inches, and are expected to increase to 35 inches by 2100.

An additional 2° rise in the global temperature will result in complete melting of the Greenland ice cap, which, in turn, will cause the sea level to rise by 5 - 6 meters. In such a scenario, low-lying areas, such as the US Gulf Coast and Bangladesh, and small islands, like the Lakshadweep and Tuvalu, will submerge.

If the whole of the Antarctic ice sheet melts, the global sea level is expected to rise by 10.5 meters.

Drastic Changes in Climate Patterns
Global warming will also alter the climatic patterns of the planet. Precipitation, for instance, will increase in equatorial, polar, and sub-polar regions, and decrease in subtropics. As a result of this, some regions will experience drought, while others will witness floods.

If the near-surface temperature increases, it will increase the temperature of ocean water. This, in turn, will increase the frequency of hurricanes. Overall, the planet will experience extreme weather conditions, characterized by flood and droughts, heat waves and cold waves, and extreme storms, like hurricanes and tornadoes.

Widespread Extinction of Flora and Fauna
According to the Intergovernmental Panel on (IPCC), an increase in global temperature by 1.5 - 2.5° will make 20 - 30 percent of species vulnerable to extinction, while a rise of about 3.5° will make 40 - 70 percent species vulnerable. Climate change will result in loss of habitat for species like polar bears and tropical frogs. It will also affect the migration patterns of various species of birds. Like animals, even humans will be affected by irregular patterns of precipitation.

Effects on Us Humans
Global warming will affect our food and water supplies as well as our health conditions. Changes in precipitation will affect agriculture, power production, etc. Similarly, an increase in the temperature of ocean waters will hamper fisheries. The sudden change in climate patterns will have a hazardous effect on the human body, which won't be able to endure the extreme conditions.

Increase in natural calamities like storms and floods, will lead to heavy human casualties. There will be a spurge in infectious diseases, as conditions will be perfect for disease-transmitting insects to breed. Many people will die of malnutrition as food production will decrease due to frequent droughts and floods.

Many people argue that global warming is a slow process and centuries will pass before its devastating effects even become obvious. These people conveniently ignore the fact that the rate at which we are fueling this hazard has also increased. We have already done enough of damage. It's high time we put things in perspective. We may not live to face its dreaded consequences, but our future generations surely will.