The Heating and the Cooling of the Earth:
The Heating and Cooling
So, what aspects of human activity have caused this recent temperature rise and what do we humans have to do differently to stop this trend. After we have established how to stop the increase we will discuss how to reverse the trend.
First let’s get an understanding of how the world is heated and how does it maintain the relatively constant temperature we have experienced for the last few thousand years. The following figure taken from Wikipedia “Outgoing longwave radiation” represents the energy coming in from the sun and the energy radiated by the Earth back into space. The energy received from the Sun is at a quite different wave length, band width if you like, than the energy radiated out by the Earth. Radiation from the Sun heats the world and Radiation by the Earth reduces the heated world and if these two are equal in terms of total energy the world’s temperature remains constant .
So, what aspects of human activity have caused this recent temperature rise and what do we humans have to do differently to stop this trend. After we have established how to stop the increase we will discuss how to reverse the trend.
First let’s get an understanding of how the world is heated and how does it maintain the relatively constant temperature we have experienced for the last few thousand years. The following figure taken from Wikipedia “Outgoing longwave radiation” represents the energy coming in from the sun and the energy radiated by the Earth back into space. The energy received from the Sun is at a quite different wave length, band width if you like, than the energy radiated out by the Earth. Radiation from the Sun heats the world and Radiation by the Earth reduces the heated world and if these two are equal in terms of total energy the world’s temperature remains constant .
These curves are calculated based on the physics of so-called Black-body radiation which is discussed in wikipedia under that title.
In these examples the sun’s average temperature is 5,500 deg. C and the Earth’s average temperature is -20 deg C.
On the vertical scale is the intensity of the radiation, often called irradiation.
These representations are for illustration and we now turn to actual measurements.For a more complete description of the relationship between wavelength, frequency and the speed of light visit Appendix 1 at the end of this site.