What is Global Dimming?

Most of us have heard of the term Global Warming. But what about the lesser known Global Dimming?

Global Dimming describes the reduction of sunlight reaching the earth’s surface, causing the sky to become darker and darker. In fact, since the 1960s, there has been a substantial decline in the amount of sunlight reaching earth’s surface. Global Dimming does affect each country differently, so the amount of dimming differs.

Global Dimming occurs when small particles from fossil fuels and other pollutants, known as aerosols, absorb solar energy and reflect back into space, resulting in a reduction in the amount of solar radiation at the Earth’s surface. This creates cooling effects, decreasing the amounts of direct and diffuse solar radiation reaching the surface of the Earth. Global dimming also interferes with the hydrological cycles and reduces evaporation rates. This could cause a decrease in precipitation. Because of the location of these particles, it impacts cloud formation which has subsequent issues.

Global Dimming actually produces opposite effects to global warming, since it produces cooling. So, is the phenomenon beneficial to the environment? Although global cooling can benefit the environment, it can also bring darkness and other issues as well.

Aerosols that come from factories, fires, and many other industrial pollutants (known as anthropogenic aerosol sources), can cause global warming, dangerous air pollution and even the swift increase in glacier melting.

There are also aerosols that come from natural sources such as volcanoes. Natural aerosol sources can reduce greenhouse gas warming and could cool the Earth. Natural aerosol sources can have much more powerful impacts than anthropogenic sources.

The pollutants that cause global dimming can lead to warming, cooling, smog, acid rain, and the destruction of natural ecosystems and habitats. Additionally, aerosols can create problems for human health. It can introduce more industrial pollutants to the environment and cause serious respiratory issues and infections.

For this reason, global dimming is sometimes known as a “devil’s bargain”. It has the potential to help the environment, but it could also cause serious harm. The real question is: Are we willing to take that risk?

Sources:

https://www.scientistswarning.org/2020/06/04/dimming-dilemma/

https://www.conserve-energy-future.com/causes-and-effects-of-global-dimming.php

https://earthsky.org/earth/earth-is-dimming-due-to-climate-change/