The anti-greenhouse effect is a process that occurs when energy from a celestial object's sun is absorbed or scattered by the object's upper atmosphere, preventing that energy from reaching the surface, which results in surface cooling – the opposite of the greenhouse effect. In an ideal case where the upper atmosphere absorbs all sunlight and is nearly transparent to infrared (heat) energy from the surface, the surface temperature would be reduced by 16%, which is a significant amount of cooling. This case is described in more detail below. Coined by Dr. Christopher McKay in 1991, the anti-greenhouse effect was first observed on Saturn's moon, Titan. In Titan's stratosphere, a haze composed of organic aerosol particles simultaneously absorbs solar radiation and is nearly transparent to infrared energy from Titan's surface. This acts to reduce solar energy reaching the surface and lets infrared energy escape, cooling Titan's surface. Titan has both a greenhouse and an anti-greenhouse effect which compete with one another. The greenhouse effect warms Titan by 21 K while the anti-greenhouse effect cools Titan by 9 K, so the net warming is 12 K (= 21 K - 9 K). It has been suggested that Earth potentially had a similar haze in the Archean eon, causing an anti-greenhouse effect. It is theorized that this haze helped to regulate and stabilize early Earth's climate. Other atmospheric phenomena besides organic hazes act similarly to the anti-greenhouse effect, such as Earth's stratospheric ozone layer and thermosphere, particles formed and emitted from volcanoes, nuclear fallout, and dust in Mars's upper atmosphere. Outside of the Solar system, calculations of the impact of these hazes on the thermal structure of exoplanets have been conducted. Energy balance theory Energy balance To understand how the anti-greenhouse effect impacts a planet or large moon with its host star as an external source of energy, an energy budget can be calculated, similar to how it is done for Earth. For each component in the system, incoming energy needs to equal outgoing energy to uphold the conservation of energy and remain at a constant temperature. If one energy contributor is larger than the other, there is an energy imbalance and the temperature of an object will change to reestablish a balance. Energy sources across the whole electromagnetic spectrum need to be accounted for when calculating the energy balance. In the case of Earth, for example, a balance is struck between incoming