According to a study published in Nature climate change, dust blowing on top of the snow-clad Himalayan mountains could be expediting the speed of snow melting. It is because dust can absorb sunlight, subsequently heating up the surrounding area. Also, it is not the garden-variety amount of dust that barely manages to make you sneeze. There is a lot of it, large enough amount to heat snow.
While rapidly melting polar snow, caps are a matter of concern, regular snow melting is also part of natural ecology. Glaciers, which feed into freshwater rivers, are resultant of normal snowmelt procedure. It is estimated that nearly 700 million people of Southeast Asia are dependent on Himalayan snow for their freshwater needs.
A former study conducted by NASA measured elevation, aerosols, and surface features like presence of dust/pollution on snow. The phenomenon these particles result in is called the Albedo Effect.
Albedo is a measure of the reflectivity of a surface. The albedo effect when applied to the Earth is a measure of how much of the Sun’s energy is reflected into space. Overall, the Earth’s albedo has a cooling effect. (The term ‘albedo’ is derived from the Latin for ‘whiteness’).
Here on Earth, the albedo effect has a significant impact on our climate. The lower the albedo, the more radiation from the Sun that gets absorbed by the planet, and temperatures will rise. If the albedo is higher, and the Earth is more reflective, more of the radiation is returned to space, and the planet cools.
An example of this albedo effect is the snow temperature feedback. When you have a snow-covered area, it reflects a lot of radiation. Therefore you can get terrible sunburns when you’re skiing. But then when the snow-covered area warms and melts, the albedo goes down. More sunlight is absorbed in the area and the temperatures increase. Climate scientists are concerned that global warming will cause the polar ice caps to melt. With these melting caps, dark ocean water will absorb more sunlight, and contribute even more to global warming.
Ice-albedo feedback is a potentially important destabilizing effect for the climate of terrestrial planets. It is based on the positive feedback between decreasing surface temperatures, an increase of snow and ice cover, and an associated increase in planetary albedo, which then further decreases surface temperature.