Global Dimming and Global Warming – Are They Connected?

I recently heard a new term that I have never encountered before. It’s called “global dimming”. Simply put, global dimming is the reduction of heat that reaches Earth because the sun’s heat and energy is being reflected back out into space. Global dimming is a relatively new phenomenon because there are more pollutants in the atmosphere then ever before. The increase in pollutants has increased cloud coverage, which means less sunlight reaches earth. Since less sunlight reaches the earth, this means the earth stays cooler.

At first, I thought that global dimming must be a good thing – something to counter-act global warming. But it also has other effects. Leading scientists think that global dimming is responsible for the droughts in Africa, causing famines that have killed millions. This is due to the fact that the water in the northern hemisphere is cooler. Cooler water means less rain. It’s a scary thought that the pollution from cars and factories in Europe and North America has killed millions of people on another continent. Even scarier when that train of thought leads me to think that if what we do in North America effects other continents, then what other continents do will also effect us.

And if you look closer, you will see that global dimming itself is caused by increased pollution. Increased pollution creates smog (making it harder to breathe) and acid rain. So, it would not be a good thing to try and increase global dimming as a way to eliminate global warming.

So, let’s take a look at global warming. Global warming causes heat waves, glaciers to melt, increased ocean levels and more. The main cause of global warming is the increasing levels of greenhouse gases, which trap heat in the atmosphere. The main contributors to greenhouse gases are things that cause carbon dioxide, such as cars and the production of electricity. Consider that the United States alone contributes 25% of the pollution that causes global warming. Then take a look at Asia, which is rapidly expanding. Asia’s demand for electricity and the number of cars on the road has skyrocketed in the past few years and it’s only expected to increase as their economy becomes stronger.

Global dimming and global warming share a complex relationship. They offset each other to some degree. Try to control only one, and the effect of the other one will be felt more. Europe has made good progress in reducing air pollution, a main component of global dimming. Therefore, it would appear that Europe is winning the battle against global dimming, but the result has been that the effects of global warming are being felt more now than ever. Europe has been experiencing record breaking heat waves like never before. To truly win the battle we need to fight both global dimming and global warming. Together.

 

To learn more about global dimming and other environmental issues, please visit these websites:

Global Issues  Social, political, economic and environmental issues that affect us all.

David Suzuki Foundation  Working to find ways for society to live in balance with the natural world that sustains us.

 

 

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