What is an Energy Balance Model?¶
An energy balance model is a very simple representation of the Earth’s climate that focuses on its temperature.
The energy coming into the Earth has to be equal to the energy leaving the Earth. That means we can balance the equations of flux into and out of the Earth (that is where the name “Energy Balance Model” is derived). Balancing these equations allows us to solve for the temperature of the Earth’s surface.
There is one significant source of energy flux into the Earth that we account for: the Sun. The majority of the energy is absorbed by the Earth itself, but some is reflected back into space (exactly how much depends on the planet’s albedo, which we’ll discuss in detail later).
At the simplest level, that is an adequate energy balance model. To be able to accurately measure the planet’s temperrature, however, we need to incorporate the Earth’s atmosphere, which both reflects energy back onto Earth’s surface, causing the Greenhouse Effect.
I’ve included an image above that illustrates the main processes, but don’t be intimidated by the equations; we’ll explain them in the next seciton. For now, all you need to imagine is energy flowing into and out of the planet.