What is global dimming?
Global dimming happens when the amount of sun’s energy reaching the Earth’s surface decreases. This phenomenon is mainly caused by air pollution from human activity.
Global warming became very alarming since the evidence of destruction started to appear on the planet. However, there is another phenomenon that could cause many destructions and leave the planet in complete darkness. This phenomenon is called global dimming.
Global dimming refers to the decrease in the amount of sun’s energy reaching the Earth’s surface. This phenomenon is caused by small particles that are released by fuels, forest fires, ash, soot, and air pollution from human activity. These particles can reach the stratosphere and retain the sunlights, which could reduce the temperatures and bring darkness to the planet.
This phenomenon was first detected in the 1950s. Gerry Stanhill, an English scientist, published a study where he compared the measurements of solar radiation at that moment with the measurements from the 1950s. He discovered solar radiation considerably decreased, but it was until January 2005 this phenomenon became worrying due to a documentary called Horizon published by BBC News.
Global dimming is not the same in the whole world. Its intensity changes depending on the region. The southern hemisphere has presented small dimming until now, while the northern hemisphere has presented significant reductions: from 4 to 8%. Regions such as North America and Europe have witnessed a decrease in global dimming, while in countries like India and China the dimming has increased.
One of the effects of global dimming is the ice age. As the northern hemisphere has presented a reduction in the solar radiation, this has resulted in colder water. This phenomenon can also affect photosynthesis due to a decrease in sun’s energy. Indeed, there is evidence global dimming have some impact in the warming caused by greenhouse gasses.
It seems air pollution from human activity is the main factor that has caused global dimming. It is very important that people contribute to the reduction of air pollution, so the effects of this and other phenomena will decrease.