As described in What is the Greenhouse Effect?, solar energy is naturally retained by our atmosphere. The natural greenhouse effect is necessary for life on Earth to exist. To specifically address the effects humans have on this process, the term "Enhanced Greenhouse Effect" is used. The implicit understanding with this term is that we are increasing the concentration of greenhouse gases in our atmosphere. This in turn leads to a further retention of solar energy and thus more warming of our atmosphere. In this sense, enhanced greenhouse effect and global warming go hand in hand, since the former leads directly to the latter. The questions become more sticky when we try to discern how much of the greenhouse effect is natural and how much is enhanced by anthropogenic (human induced) causes.