# The Azimuth Project Ice albedo effect

## Idea

The ice albedo effect is simply a name for how ice and snow reflect solar radiation, and thus help keep the Earth cool. Since a cool Earth also tends to have more ice and snow, the ice albedo effect is an example of a positive climate feedback. If a snow-covered area warms and the snow melts, the albedo decreases, more sunlight is absorbed, and the temperature tends to increase. Conversely, if snow forms, this tends to decrease the temperature. This effect may be important for the glacial cycles and also for Snowball Earth events in the early history of the Earth.

The AR4 WG1 report? gives estimates of the ice albedo effect for the entire Earth that range from 0.07 to 0.34 W/m2/K. In other words: if Earth’s average temperature increases by 1 °C, it absorb somewhere between 0.07 to 0.34 watts per square meter of solar radiation. For details, see:

The albedo is a measure of how much radiation an object reflects. A perfectly white surface has albedo 1, while one that is perfectly black has albedo 0. Fresh snow has an albedo of 0.8 to 0.9, while ocean ice has an albedo of 0.5 to 0.7.

In the following chart, albedos are instead shown as ranging from 0% to 100%:

## References

Much of this information was taken from

The chart was created by Hannes Grobe.

category: climate