General Studies : Climate change and Global warming

The terms climate change and global warming are used in narrow meaning and broad meaning. In narrow meaning it refers to the recent change in climate change brought out by mainly by man’s activities (this is what we usually see and read in newspapers). In broader term it refers to the change in climate that has occurred on earth from historic times.

About the climate change (from early times):

The climate change has been a phenomenon that has been occurring since the creation of earth. The causes are many; some of major ones are given below:

Plate tectonics: We know that earth surface (oceans and continents) are made of plates. These plates move over time. The movement changes the amount as well as duration of sunlight at a given place. Eg: a place which is located at poles at an early point in time moves to equator. Here the sunlight received at that given point will be more when situated near equator. The land/water ratio at any given latitude also changes with plate tectonics. The “movement of plates” is an accepted phenomenon, and so is its role in climate change.

Volcanoes: Volcanoes bring loads of dust, carbon dioxide and heat when they explode. The dust reduces the amount of sunlight reaching earth surface. As a result cooling occurs. In earth’s history we know of many instances where earth was cooled as a result of the volcanoes. The co2 on the other hand will increase temperature, the manifestation of this will occur after certain time.

Earth’s orbital variation: Does earth always revolve in same path. Earth too has its freedom. As a result there is change in the path (large orbit or smaller orbit---eccentricity), tilt (earth normally has a tilt; this would increase of decrease sometimes). These changes in the earth’s motion path will lead to change in amount of sunlight it receives(Malkovich cycles). Change in sun’s energy = change in insolation=change in climate

Sun: We read about earth changing it path. Sun too has its freedom; it will glow at low intensity at certain times and glow with more brightness at some other time(sun spot activity). The change in sun’s energy (cause internal to sun) = change in insolation=climate change.

These forces mentioned above where happily changing climate in past. Now that we humans have increased exponentially, we too have decided to be a cause for changing climate. All the ways we change climate are listed as anthropogenic causes. In recent decade, we have become the major factor which influences climate change. The activities like deforestation, burning fossil fuels, release of cfc’s etc are changing the climate at a rapid pace.There is a set of scientists (minority) who believes that man is not a major factor but other factors mentioned above are the reason for present climate change.

About the recent climate change (in the last decades):

The concept of change in climate due to man’s activities has been there in scientific literature for over a century. It was the IPCC assessment that created a wide awareness and consensus about the issue. Now majority of the scientists accept that the “climate change and global warming” has occurred in recent times at an alarming pace and that man has played a major role in creating it.