Simplest Climate Model

To understand the complex climate model first, we need to understand the most basic climate model and in future articles, we will explore the more complex and ignored concepts in this model. This model is the threshold of climate modelling having a lot of inconsistency.

First, let us understand how heat energy is produced. The heat energy is produced by oscillating of atom/molecule. The reason why you burn your skin is that motion of atoms in your skin is increased by coming in contact with a hotter object. This, in turn, rips apart the chemical bonds of your skin ultimately resulting in a burn.

Particularly when we are dealing with earth sciences we are dealing with light energy coming from the sun by radiation. Then you might ask that earth is covered by an atmospheric blanket, how exactly can heat energy come in earth. The answer is earth is a blackbody. A blackbody is an object that oscillators at all different frequency and absorbing all incident electromagnetic radiation. The energy coming from the sun is light energy which is electromagnetic radiation. Earth acts as a cavity for the incoming energy from the sun.

But according to the law of conservation of energy, the earth should not warm itself up on its own. The warming effect is due to the greenhouse effect. We will discuss greenhouse effect on further modification of this model in future articles. In this model, for the sake of simplification, we have considered the ground temperature constant across the earth.

All the energy coming in the earth is given by

                                                             =L(1-ɑ)A --------1

Where, L= Solar energy constant= 1350watt/m²

               ɑ= Fraction of light that gets reflected=33%(For earth)

            A= Area of earth’s shadow=πR²

All the energy going out of the earth or total energy flux is given by

=ƐσT⁴4πR² --------2

Where Ɛ= Emissivity(It is the extent up to which an object is a blackbody)=1

            σ= Stefan–Boltzmann constant=5.67*10^-8 Wm^-2K^-4

            T= Temperature of earth

            R= Radius of earth

According to the law of conservation of energy, energy coming in the earth should be equal to energy going out. 

Energy in= Energy out

Putting values and from eq1 &2

L(1-ɑ)πR²=ƐσT⁴4πR²

T=253K

Fact- Venus is not bright because of energy flux(light going out) but because of the reflection from the dense clouds that do not let sunlight enter its atmosphere.

A small exercise considering the model we have created and the actual variation of data.

The actual temperature of the earth is 288K and we have measured 253K temperature. This inconsistency is due to the majority of the wrong assumption we considered. This is a basic model and acts as a low-resolution interpretation of climate but it is a place of the threshold of complex climate models. For higher resolution climate model stick around.