Global Warming: Everything you need to know

By Malik Sarmad Nauman

Global warming has been a serious environmental issue since the last two decades. Global warming is “the increase in the average temperature of Earth’s surface and its oceans due to greenhouse gas emissions such as methane, carbon dioxide, nitrous oxide, and ozone etc.” Earth’s average surface temperature rose from 0.6 to 0.9 degree Celsius between 1906 and 2005 and the rate of increase in temperature has been doubled in the last fifty years. NASA estimated that the increase in temperature will go up further.

HowStuffWorks defines global warming as:

“Global warming is a significant increase in the Earth’s climatic temperature over a relatively short period of time as a result of human activities. In specific terms, an increase of 1 or more degrees Celsius in a period of 100 to 200 years would be considered global warming. Over the course of a single century, an increase of even 0.4 degrees Celsius would be significant”.

How Green House Gases Cause Global Warming???

Greenhouse gases cause global warming due to “greenhouse effect”. The greenhouse effect can be explained by the diagram below:

Greenhouse gases are always present in the Earth’s atmosphere. Normally, the radiation is coming from the sun, some of which is absorbed by the Earth’s surface and the remaining radiation is reflected back into the atmosphere.

The radiation that is reflected back is Infra-red (IR) in nature. This IR radiation is either absorbed by greenhouse gases that are present in the atmosphere or re-emitted in all directions. This results in the increasing temperature of the earth. This effect is known as the greenhouse effect and this is how it causes global warming.

Facts about Global Warming:

Following are some of the important facts that we must know:

  • Global warming is happening due to the emission of greenhouse gases which are required for the existence of human life on Earth but the major culprit is their over emission.
  • Greenhouse gases like carbon dioxide, methane and nitrous oxide etc. remain in the environment for longer periods of time. It means these gases have a longer residence time in the atmosphere which makes the condition more severe.
  • Human activities are estimated to have caused approximately 1.0°C of global warming above pre-industrial levels with a likely range of 0.8°C to 1.2°C.
  • Global warming is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate. (IPCC)
  • According to climate studies, the last two decades of the 20th century have been warmer in the last 400 years.
  • The region which has been severely affected due to global warming is the Arctic region. The Arctic is melting rapidly. It is estimated that by the year 2040, the region will have a completely ice-free summer.
  • The average temperature in Alaska, Western Canada, and Russia has risen at twice the global average. (Multinational Arctic Climate Impact Assessment Report , 2000 – 2004)

Sources of Global Warming :

The sources of global warming fall into two categories: 

  • Natural 
  • Anthropogenic 

Natural Sources of Global Warming: 

The natural sources of global warming include; vegetation decay, wild fires, volcanic activity, paddy fields etc. All these sources are responsible for the emission of greenhouse gases in the atmosphere which leads towards greenhouse effect or in other words global warming. Vegetation decay by anaerobic bacteria is the major source for the production of methane (CH4) which leads to global warming. 

Anthropogenic Sources of Global Warming: 

Anthropogenic sources are related to human activities. The anthropogenic sources of global warming include; burning fossil fuels (i.e. coal, oil, and natural gas), burning of wood, deforestation, use of chlorofluorocarbons (CFCs) etc. The combustion of fossil fuels is the major source for the production of greenhouse gases like CO2, NOx, and SOx. Trees are a major source of diminishing CO2 so the removal of trees allowingthe continuous addition of CO2 into the atmosphere causes global warming. 

Effects of Global Warming:

  • Climate change 
  • Loss of islands due to a rise in sea levels 
  • Higher winter rainfall – lower summer rainfall 
  • Loss of aquatic resources due to rise in temperature 
  • Loss of vegetation due to reduced soil moisture 
  • Loss of aquatic resources due to rise in temperature 
  • Flash floods 
  • Glaciers melting

Climate Change:

Climate change is one of the major crises that humanity is facing. It is the change in rainfall/precipitation patterns due to arise in the temperature of the Earth. It is a change in global or regional climate patterns due to increased levels of carbon dioxide in the atmosphere by the use of fossil fuels. Climate change is apparent from the mid-20th centuryonwards. The results of warming temperatures can be seen in the diagram below: 

The warming of earth results in the melting of glaciers due to which sea level is rising. The rise in sea level may result in coastal flooding and damage the areas near the sea coast. The change in climatic patterns has disturbed the duration of summer and winter rainfall. The span of summer rainfall has shortened as compared to winter rainfall. 

“There’s one issue that will define the contours of this century more dramatically than any other, and that is the urgent threat of a changing climate” (Barack Obama – Former President of the United States of America). 

The opinions in this article are of the writer only and do not represent the views of The Weekly Pakistan.

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