GLOBAL WARMING

 Global warming is a long-term rise in the earth’s temperature. Global warming is attributed to human intervention.

Since the pre-industrial period, human activities are estimated to have increased Earth’s global average temperature by about 1 degree Celsius (1.8 degrees Fahrenheit), a number that is currently increasing by 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade. It is unequivocal that human influence has warmed the atmosphere, ocean, and land(1).

 Global warming is mainly caused by the global rise in greenhouse gases. Such as carbon dioxide, methane, nitrous oxide, etc. These gases are mainly produced by the burning of fossil fuels.  After the 1800s there is a rise in the use of fossil fuels, so there is also a rise in these gases in the atmosphere. Carbon dioxide has increased to 48% in the previous century. The rise in greenhouse gases has a blanket effect on global temperature. As these gases make the earth a glasshouse.

 These gases trap the infrared radiations from the earth and keep the earth warm.

  THE effect of these gases has pushed the ice age 1000 years away. If these gases were not increased in the atmosphere there must be Ice Age on earth.

GREENHOUSE GASES(2)

Carbon dioxide

Methane

Nitrous oxide

Tetra-fluoro-methane

Hexa-fluoro-ethane

Sulfur hexafluoride

Tetra-fluoro ethane

Difluoroethane

The greenhouse gases that also cause ozone layer depletion are-

CFCs, Halon-1211, halon 1301, and carbon tetrachloride, methyl- chloroform.

GREENHOUSE EFFECT

This is a well-known phenomenon, where a green glasshouse is used to grow fruits and vegetables at low temperatures. Glass house keeps the area warm and protects the plants from cold shock.

Greenhouse gases such as CO2, Methane CH4, Nitrous oxide N2O, and sulfur hexafluoride SF6 trap the heat radiated by the earth and keep the earth warm.

Earth receives solar radiation in the form of short waves. Of these solar radiations, a large amount of 30% is reflected back. 23% is absorbed by clouds, dust, and CO2. Solar radiations absorbed by land and ocean heat up land and water. This heat is radiated by the earth in the form of long waves. This heat is radiated through conduction and the latent heat of the earth. These long-wavelength radiations are absorbed by H2O, CO2, CH4, and other greenhouse gases. These radiations are then radiated in different directions by these gases. This keeps the earth warm. This is called the greenhouse effect.  

Global warming

  

Major greenhouse gases

Water vapors

This is a major contributor to greenhouse gases. Water vapors are present in large amounts in the atmosphere. So, these absorb a large amount of long-wave radiation from the earth and keep the earth warm.

Carbon dioxide

This gas is produced by burning fossil fuels. It is produced by volcanic eruptions. This gas is also produced by respiration. This gas is a major greenhouse gas. This gas has increased 250 times from 1850 to 2020. This gas has caused the global rise in average temperature. 

Methane

It is also called marsh gas. It is produced by marshes, paddy fields, and cattle. This gas is used as fuel. It is a very potent greenhouse gas.

Nitrous oxide

This is also known as laughing gas. N2O is produced by burning fossil fuels. This also radiates long-wavelength radiation. 

Ozone

It is also a greenhouse gas.

CFCs

These gases are synthetic gases. These gases cause ozone layer depletion. These are also greenhouse gases.

IMPACT OF GLOBAL WARMING

Global warming is one of the factors of climate change. It has impacted the global climate. It has changed the crop cycle. It has resulted in the melting of the ice cap. It is responsible for sea-level rise. It has adversely impacted coral reefs. It has adverse effects on the Antarctic and Arctic ice sheets.

Extreme weather phenomenon.

Global warming has caused global ice melting. This is destructive to the alpine ecosystem. This also causes a rise in sea level. This causes submergence of low land areas, and even a threat to some islands.

This impacts El-Nino and la-Nina also. Thus causing more severe drought and floods respectively in India.

Inland water resources are depleting. Lakes and rivers are drying.

Deserts are expanding.

Forest fires are now becoming more common and severe.

Severe rain and drought conditions have become a common phenomenon.

The rise in CO2 levels in the atmosphere also causes acidification of the ocean.

Ocean temperature rises due to global warming, which has an adverse impact oceanic ecosystem. It is also destructive to coral reefs.

The last decade has been the warmest decade of this century.