Now, if you are familiar with my site (or have a decent background in climate science), you will recognize the term ‘Greenhouse Effect’ and what it does. But what you may not realize is that the Greenhouse Effect is key to all life on Earth. Without it, the Earth would be like Mars – frozen and empty.
Let me tell you what I mean.
What is Albedo?
Earth gets its warmth from the sun. Beams of light and radiation travel across space and warm all that they touch. Yet why is Earth so friendly to life, while Mars is a frozen rock?
Before I answer, I have to do some explaining.
All objects have something called albedo. Albedo is, to put it simply, a way to measure how much light an object reflects. Ice, for example, has a high albedo, while asphalt has a low albedo (you don’t see your reflection in the pavement, do you?). Earth’s Albedo is about 0.3, which means that about thirty percent of all light that hits Earth gets reflected back into space. This doesn’t seem like much, but it means that by all calculations, the earth should be frozen and utterly inhospitable. But as anyone can tell from simply looking around, that isn’t the case. So, why is that?
The answer lies in the atmosphere.
The light that bounces off the earth gets caught by molecules in the earth's atmosphere, mainly methane and carbon dioxide. That light then heats the earth like a Greenhouse would, thus increasing the earth’s temperature and leaving it habitable for life. That’s right. The very Greenhouse Effect that is so controversial is one of the main reasons that our planet can support life at all.
So why is the Greenhouse Effect an issue now?
By burning fossil fuels and other sources of pollution, we add more carbon dioxide and methane into the atmosphere. This strengthens the Greenhouse Effect, and thus increases Earth's temperature. More ice melts because of the increase in heat, which lowers Earth's overall Albedo.
This means that the earth reflects less light, which results in the earth getting hotter causing more ice to melt. More melting ice means the earth reflects less light, which means...I think you get the idea. This process of constant repetition is referred to as the Albedo Positive Feedback Loop (see the image on the right).
In short, the Greenhouse Effect is one of the main reasons why Earth can sustain life even in the cold of space. However, human activity is overloading the Greenhouse Effect, thus warming the earth’s surface faster than it would naturally on its own.
From Understanding to Action
Let’s face it; most of us aren’t really in a personal position to change the world. I’m not a world leader. I’m not a major shareholder in a large oil company. We can’t change the world through our own, immediate actions. But when we understand the science at play, when we discover the origin of a problem, we can come together to find a solution.
Until next time,
Jackson
Here's a great resource with lots of information about albedo:
If you want to check out the concept behind albedo for yourself, here’s a link to a quick and easy experiment that demonstrates the basic principles of albedo and what’s happening to our planet. Here are two good options:
When you do that experiment of the solar oven, which material do you think has a higher albedo – tin foil or black paper?
If you are interested in a more technical analysis of the major climate change news over the past year (2023), check out my recent blog by clicking here.
Image Sources:
Albedo Effect Graphic: https://www.cbsnews.com/tag/science-of-weather/
Albedo Positive Feedback Loop https://serc.carleton.edu/details/images/17956.htm