Presentation on theme: "The Earth’s Radiation Budget 3:35 The Earth’s Energy Balance."— Presentation transcript:
The Earth’s Radiation Budget http://www.youtube.com/watch?v=DOAqECd70Ww&safe=active 3:35 The Earth’s Energy Balance
The Earth’s Radiation Budget is how much of the sun’s energy is absorbed by the earth versus how much of it is reflected back out to space. Approximately 71% is absorbed in total (23 + 48)
If the Earth and it’s atmosphere keep more solar energy than it sends back to space, the Earth will warm up. If more energy is sent back to space than is kept by the Earth and it’s atmosphere, the Earth will cool down.
Scientists think of the Radiation Budget in terms of a see-saw or balance. When absorbed sunlight and reflected energy balance each other, the Earth's temperature doesn't change - the radiation budget is in balance.
Climate Change The temperature of the planet depends on the balance between how much of the sun’s radiation is absorbed by the earth vs. how much is reflected. The trapped heat keeps the planet warm and the heating process is called the greenhouse effect. The greenhouse effect has been crucial to maintaining earth’s energy balance and temperature throughout its history, making the planet habitable. Recently, scientists have concluded that earth’s energy system is out of balance, as increasing concentrations of greenhouse gases are causing additional heat to be absorbed. As of 2007, scientists are over 90% certain that human-caused greenhouse gas emissions have caused the global increase in average temperature by about 1 o C since the mid-20th century. http://www.youtube.com/watch?v=3JX-ioSmNW8&safe=active 2:03 Greenhouse Gases: Climate Change, Lines of Evidence
The Electromagnetic Spectrum The heat produced by the Sun travels to the Earth as waves known as electromagnetic waves. The electromagnetic waves come in a variety of lengths. The name given to the full range of all the wavelength is the electromagnetic spectrum.