Global Dimming

Table of Contents

Global dimming is defined as the decrease in the amounts of solar radiation reaching the surface of the Earth.
The by-product of fossil fuels are tiny particles or pollutants which absorb solar energy and reflect back sunlight into the space.
Aerosols have been found to be the major cause of global dimming.
The burning of fossil fuels by industry and internal combustion engines emits by-products such as sulfur dioxide, soot and ash.
These together form particulate pollution —primarily called aerosols. Aerosols acts as precursor to global dimming in the following two ways:
These particle matters enter the atmosphere and directly absorb solar energy and reflect radiation back into the space, before it reaches the planet’s surface.
Water droplets containing these air-borne particles form polluted clouds. These polluted clouds have heavier and larger number of droplets. These changed properties of the cloud – such clouds are called ‘brown clouds’ – makes them more reflective.

EFFECTS

Both global dimming and global warming have been happening all over the world and together they have caused severe changes in the rainfall patterns.
It is also believed that it was global dimming behind the 1984 Saharan drought that killed millions of people in sub-Saharan Africa. Scientists believe that despite the cooling effect created by global dimming, the earth’s temperature has increased by more than 1 deg. in last century. If global dimming wouldn’t have happened, the temperature of this planet would be much higher and could have posed a serious effect o the lives of humans, plants and animals
A growing concern is the impact of global dimming on Asian monsoons which cause 50% of the world’s annual rainfall. If this happens, then half of the world’s population will be starving.
decrease in sunlight or solar radiation will negatively impact process of photosynthesis in plants.
Global dimming is thought to be counteracting the actual effect of carbon emissions on global warming. So, if efforts are made to reduce particulate emission causing global dimming, it will enhance global warming and increase the global temperatures to more than double.
This will make planet Earth, almost uninhabitable. To prevent this situation, it is important that emission of both greenhouse gases and particulate matter should be reduced simultaneously. This will balance out both the phenomena.