Environment Counts | The increasing greenhouse effect
Author: Geoff Zeiss – Published At: 2011-11-21 10:48 – (835 Reads)
The balance between absorbed solar energy and radiated energy of the Earth is being changed by the increasing greenhouse effect which leads to a net energy inflow of about 1 Watt/square meter.
Because the Earth’s surface has warmed by about 0.8 Â° C since 1900, radiation from the earth’s surface (396 W/mÂ²) has increased by about 5 W/mÂ². Absorption from the atmosphere by the surface has increased by about the same amount. The result is a net energy inflow of about 1 W/mÂ², which compared to the energy 0.03 W/mÂ² generated directly by humans, is significant.
Energy from the sun
|Radiation from the sun||341 W/mÂ²|
|Absorbed by atmosphere||-78 W/mÂ²|
|Reflected by clouds and aerosols||-79 W/mÂ²|
|Reflected by Earth’s surface||-23 W/mÂ²|
|Absorbed by Earth’s surface||161 W/mÂ²|
Energy loss from the Earth’s surface
|Radiation from Earth’s surface||-396 W/mÂ²|
|Convection from surface||-17 W/mÂ²|
|Evapotranspiration from surface||-80 W/mÂ²|
|Total loss from surface||-493 W/mÂ²|
|Radiation from sun||161 W/mÂ²|
|Absorbed from atmosphere||333 W/mÂ²|
|Total absorbed by surface||494 W/mÂ²|
|Total lost by surface||493 W/mÂ²|
|Net absorption||1 W/mÂ²|
|Human generated||0.03 W/mÂ²|
Approximately 161 W/mÂ² of direct solar radiation is absorbed by the Earth’s surface. 333 W/mÂ² are absorbed by the Earth’s surface from the atmosphere for a total of 494 W/mÂ².
The Earth’s surface radiates about 396 W/mÂ². Together with evapotranspiration (80 W/mÂ²) and convection (17 W/mÂ²) the Earth’s surface loses 493 W/mÂ².
The net result is an increase in absorption of about 1 W/mÂ².