Earth Warming

Over the past several decades there has been considerable concern over the possible slow rise of a few tenths of a degree Celsius in the average temperature of Earth’s atmosphere and its surface. Most of the concern seems to be associated with the greenhouse effect on the radiation from the Sun. However, assuming that the average temperature of Earth can be defined unambiguously so that the small rise in average temperature is true, can there have been additional thermal energy coming from within Earth to cause this rise?

Answer

Yes, there can be fluctuations in the thermal energy conducted and convected to Earth’s surface from sources within. There are several types of thermal energy sources, including radioactive nuclei emitting particles that transfer their kinetic energy to thermal energy, as well as friction between internal rock flows, which could create local hot spots and/or temporary changes in the flow properties of liquid rock or the thermal conductivity of the rocks. Therefore, small changes in the rates of thermal energy transport to Earth’s surface are possible and most likely happen continually. Are these internal sources the culprits in the present slow average temperature increase? These fluctuations are expected to be too small, but no one knows for sure.