As there is a reduction in sunlight’s reach on the surface of the earth it is termed as Global Dimming. One of the main causes is the stoppage in the atmosphere and the other being consumption of Aerosols. Global dimming is said to be existing from 1960-19, there was a 4% drop in the sunlight reach on earth’s surface. Clouds play an immense role in the global climate.
Researches have revealed that the earth reflects less sunlight as compared to measurements of 20 years. There has been a drastic drop in the reflecting power of the earth. It is estimated that during the last three years a major drop has occurred. Around less than half of the sunlight is sent back from the earth’s surface, but now it reflects very little. Global dimming wasn’t an issue all over the earth till 2004, even since then scientists thought it wasn’t overall earth but regional. mostly the city areas where there were many aerosol pollutants.
The story behind global dimming is because of regional issues. Earth is mostly warmer, but some regions don’t have much-polluted air. However, black carbon is said to increase global warming as per some researchers, and even Carbon dioxide. Researchers believe that black carbon can soak solar energy and moves it to the Himalayas where the glaciers melt. This can also affect Arctic ice which in turn reduces reflection and increases solar radiation absorption.
What impacts the sunlight falling on earth?
Majorly, there are two reasons, the first being the Sun’s brightness and the second being the planet’s reflecting power. The changes in the data measured did not correlate with the Sun’s brightness and that leaves us with only one other thing being that it was being caused by something on the earth.
In recent years, there has been a depletion of clouds over the eastern Pacific Ocean which are bright and reflective. Sea Surface temperatures have been increasing over the coasts of North And South America. It is said to be due to global climate change. The dimming of the earth can also be considered in terms of the how much solar energy is absorbed by the climate. The additional solar energy on the earth’s surface can lead to global warming.
Earth is dimming majorly due to the oceans being warm which in turn is causing fewer clouds that reflect sunlight into space, this traps more energy in our planet. There have been decades of Earthshine measurements, the reflective light that brightens the surface of the moon. The measurements were helpful for the Astronomers to study climate change. The NASA study has revealed that the change in the energy of the earth is doubled from 2005-2019. This tells us that more energy is being absorbed from the sun than the energy reflected in space which makes earth’s energy out of balance that makes the planet warmer.
The imbalanced energy is because of greenhouse gases like Carbon dioxide, Ozone, and Methane. Pollutants like these block the reflected energy from going back to space that increases heat within the atmosphere. Till this rate of heat decreases more climate changes can be expected than usual.