Greenhouse and Icehouse Earth - Icehouse Earth

Icehouse Earth

An "Icehouse Earth" is the earth as it experiences an ice age. Unlike a Greenhouse Earth, an Icehouse Earth has ice sheets present, and these sheets wax and wane throughout times known as glacial periods and interglacial periods. During an Icehouse Earth, greenhouse gases tend to be less abundant, and temperatures tend to be cooler globally. The Earth is currently in an icehouse stage; as ice sheets are present on both poles and brief periods which could be termed small ice ages have occurred in the past few centuries.

Understanding what causes the icehouse effect and how it can change to a greenhouse state, and then back, is important to scientists, since human life has not existed within a greenhouse environment (unlike certain ancient species like the Crocodilians).