The energy that warms Earth’s lower atmosphere comes from the Sun, but the lower atmosphere will not warm directly. This area of the atmosphere heats from underneath. As the Earth warms, it emits some longwave radiation back outside, heating up the lower atmosphere above it. This energy radiates from the atmosphere back into space.
The Earth will not consume the electromagnetic energy that hits it all. This really is significant for the World’s energy balance, because just energy that is absorbed leads to the temperature of the Earth/atmosphere system. The percentage of the overall energy reflected by the Earth (or some item) is known as the Albedo.
A totally absorptive surface has an albedo of 0, an item using an albedo of 0.5 consumes as much energy as it reflects back, and a totally reflective surface has an albedo of 1. In case the World had an albedo of 1, no energy would be absorbed by it in the Sun as well as the planet will not be a lot hotter.
The Earth’s average albedo is determined by the composition and physical state of its own surface. Procedures and multiple variables can alter the albedo of a surface with time. For instance, as soot and grime settle on fresh ice or snow, and as water turns to ice the albedo increases, the albedo decreases. Likewise, vegetation cover affects the albedo of the landscape: deserts have albedos of 20- savannas, 35% are around 15%, and rainforests are around 5%.
Seasonally, winter snow and ice cover increases the albedo of Earth’s temperate and polar areas. Exactly the same occurs with all the coming and going of ice ages, on geological timescales. The Earth’s albedo is influenced by particles. Soot particles consume energy directly, and from combustion have low albedos, leading to heating. Aerosols including sulfates that are airborne powerfully reflect shortwave radiation, so the Earth’s overall albedo raises. Clouds, which are made from condensed water vapor, additionally raise the Earth’s albedo.
Human activity effects vegetation cover, land use, as well as the concentration of soot particles, aerosols and water vapor . This makes the result of human activity on the Earth’s albedo evaluate that is hard.
Further Reading –
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