Global Warming not caused by humans?

[Future Raptor Ace]

Global Warming not caused by humans? There is global warming happening currently but it is not a result of anything humans have done according to what I have learned today.

Well today in my Heat Transfer class the Professor proposed the above idea as he stated that the Sun goes through natural hot and cold cycles. As for the temperature of the earth, since we are currently studying radiation effects, we derived a formula where one can see the temperature of the Earth depends mostly on the temperature of the Sun. Since the only form of heat energy that can travel through the vacuums of space is radiation; the temperature of the Earth depends mostly on the radiation formula below. Yes there is some conduction and convection effects due to the oceans and weather but the dominant form of heat transfer that the Earth feels is radiation from the Sun. I shall write out the temperature of the Earth formula due to radiation effects below as well as what each of the variables mean.

Temperature of earth TE
TE = [((αE*εs)/(εE))^(1/4)*(Ds/((4*dSE))^(1/2)]*Ts
αE = absorptivity of the earth. This directly means how much radiation (heat energy from the Sun) can the earth absorb. This variable will increase from an increase CO2 emissions from humans.

εs = emissivity of the Sun (how much radiation is emits)
εE = emissivity of the Earth (how much radiation the earth emits) ... which is how much radiation bounces off the earth from the sun. This variable will decrease from an increase in CO2 emissions from humans .... (green house effect)

Ds = diameter of the Sun
dSE = distance between the Sun and Earth

As you can see above; the only variables that is effected by humans (I highlighted in red) is raised to the 1/4th power which is a quad-root (4th root)! This will be a very small number which proves these variables have a negligible effect on the temperature of the Earth. Since Ts (temperature of the Sun) is the only variable not raised to a fractional power, it is the dominant variable by far in the equation.


So according to the math .... we humans contribute an insignificant amount to global warming; interesting huh?