What is Global Dimming, Causes of Global Dimming

[ABDUL JABBAR KATIAR]

The gradual decrease in the intensity of the amount of sunlight reaching to the earth’s surface is known as Global Dimming. However it aids in the process of global warming but at a relatively slow speed.

What is Global Dimming, The Causes of the Global Dimming
Global dimming is created by the pollution present on our planet caused by human activities. The presence of the aerosol particles in the atmosphere is basically responsible for destruction of our planet. The particles like aerosols absorb the sunlight, and it sent back to space again. These particles can also become nuclei for the clouds. The increase in the rate of pollution also increases the number of these particulates in the form of droplets. These droplets give rise to the clouds which are transparent and hence reflect the sunlight back into the space. These smaller droplets are also responsible for reduce amount of rain. These clouds can seize the heat from the sun as well as the radiance form the earth. The effects of these clouds are variable. In day time often these clouds often stop the sunlight from reaching to earth at large therefore leaves a much more cooling effect. However this process gradually slows down in night and the re radiance retains back some of the heat of the sun from going back to space.



What is Pan Evaporation, How Pan Evaporation Occurs
Pan evaporation is the combination of the measurement of climatic elements. These climatic elements include temperature humidity, wind and solar energy. The process of evaporation increases with increase in temperature and declines with the drop in temperature and the presence of humidity in the air. Pan evaporation method is used mostly by farmers. Unlike global warming nobody paid much attention to the process of evaporation unless the scientists in Israel and Europe found that even with increase in the global warming the rate of evaporation is still declining. Solar irradiance is labeled as the main reason for this change. Pan evaporation data is considered most authentic source for defending global dimming. However the process of pan radiation does not only depend upon the solar radiation it is also dependent upon the wind speed and speed of evaporation.



Causes of Global Pollution
There many causes of global pollution like burning of fossil fuels, smoke from the industrial chimneys, the noise and emission of gases from vehicles, artificial cooling and heating systems and deforestation. All these sources contribute to emission of immense industrial wastes, acids, fluids and gases. The presence of the gases like carbon dioxide, sulfur, black carbon and carbon monoxide has raised many problems for our survival. These pollution sources have created an imbalance in our climatic activities which has brought us to the era of global warming and global dimming. This imbalance has also resulted in lower rains and fresh water problem for our survival. The tiny particles like soot have disturbed the water cycle and we are standing on the verge of destruction. The heat from the sun is an important constituent of water cycle thus the presence of pollutants in the air has reflects back the sunlight and hence results in less water vapor. The less accumulation of water vapors result in less rains and ultimately the discrepancy in eco system. The climatic changes in the atmosphere are greatly contributed to the global dimming. The scientists believe that the heat form the sun does not reach to the earth properly therefore we do not receive rains and hence there is reduction in monsoon in many parts of the world like Africa and china. Moreover scientists also claim that the increase in pollutants decrease the size of water vapors, hence it does not transform into clouds.

source: What is Global Dimming - Causes - Global Pollution - Pan Evaporation