How is the enhanced greenhouse effect different from the greenhouse effect

The 'greenhouse effect' is how carbon dioxide, methane, water vapour and other molecules absorb the energy of specific wavelengths of electromagnetic radiation (i. e. light), and transfer parts of that energy to the atmosphere as heat. The effect stabilizes the earth's temperature at levels that permit liquid water to exist. In other words, permit life forms as we know them.

The 'enhanced greenhouse effect' is the additions to the above effects caused by human activities that increase the concentrations of greenhouse gases in the atmosphere.