Albedo Albedo Albedo: What's it all about?

This blog is about the albedo effect; according to the Oxford Dictionary, it is "the proportion of the incident light or radiation that is reflected by a surface, typically that of a planet or moon". That might sound more complex than it actually is. What it comes down to, is that some surfaces are more reflective than others.

Think of snow. Anyone who's walked around a pristine field of snow in the sun will remember barely being able to look at it. The snow reflects the sun. Other surfaces, for example asphalt, actually absorb the sunlight. They are not hard to look at on a bright day, but they can become very hot. There is a fairly simple property that governs the albedo of a certain surface, namely colour. Basically, lighter colours reflect more light than darker ones, which is why white snow is so much more difficult to look at than black asphalt.

For the planet, this means that there are some parts that act like a mirror, reflecting the incoming sunlight back into space. Ice sheets have a high albedo, meaning that they sent back much light, as do clouds. Dark ocean water, forests and most human built structures have a low albedo. They absorb more light than they reflect back.

Source: http://www.climatepedia.org/Albedo

The albedo is the percentage of light reflected. Of course, it makes sense that when we change the surfaces of the Earth, because of global warming or deforestation, the Earth's albedo will change as well. Less ice will mean less sunlight being reflected back into space, and more light being trapped on Earth - which means more heat as well and more global warming leading to more ice melting, leading to lesser albedo of the Earth's surface... In other words, through the albedo effect, global warming could potentially be exacerbated.