D. Do Microwave ovens support the Greenhouse Effect?
The following statement is frequently passed around the media and entertainment industry.
“Microwave ovens use the same principle as the greenhouse effect – generating heat by absorption of electromagnetic radiation. Astonishing that some people are incapable of accepting the basic science which they take advantage of every day.” https://realclimatescience.com/2016/08/microwave-oven-deniers/
This statement is incorrect. In a microwave oven high intensities (700 to 1200 watts) of microwaves are artificially generated and introduced into a reflective chamber. It is not the photons with a wavelength in the microwave spectra that are being absorbed that does the heating. This is also known as radiation absorption aka radiation heating.
It is the magnetic and electric fields that are carried by the microwave radiation. The extremely high intensity of microwave radiation inside the chamber creates powerful oscillating electric and magnetic fields at right angles. The electric field attracts and repels the slightly negative oxygen atom and slightly positive hydrogen atoms in the water molecule. The oscillating magnetic field pulls and pushes the accentuated electric portions of the molecule. This causes the polar parts of the molecules to stretch back and forth millions of times per second (2.4Ghz) and heats the molecules. This process is called dielectric heating. [National Research Council 1994 Microwave Processing of Materials, Washington DC, The National Academies Press. https://doi.org/10.17226/2266.] In Dielectric Heating published by Microwave Power Systems, Puschner Mikrowellen Energieetchnik stated at page 1 of their brochure:
“Contrary to convective heating with steam and hot-air, or even radiation heating in general, dielectric heating generates heat directly inside the exposed material.”
This is demonstrated by the dry ice experiment. Dry ice (solid CO2) placed in a microwave oven does not heat because CO2 is not polar. This illustrates that dielectric heating and radiation heating are different mechanisms.
The fact that the IPCC has never mentioned the microwave oven as an example of the Greenhouse Effect supports that dielectric heating it is a different mechanism.