N°3 - Is human activity powerful enough to explain global warming?

Between 1975 and 2005, an increase in temperature at the surface level of the earth of at least 0.5 [K] was recorded. Has human activity alone had enough power to generate the heat necessary to warm up the billions of tons of rocks, water and air?

A rigorous calculation would be extremely complex, because in order to compute the quantity of energy corresponding to an increase of 0.5 [K] at the land and ocean surface, we would have to:

Account for the concomitant increase in energy losses towards space
Account for the energetic storage that is due to the increase of the water vapor and convection in the atmosphere and the oceans
Account for the melting of the ice sheets, for the evolution of the cloud cover, and for the modification of the corresponding emissivity of the planet
Account for the eventual increase in wild forest fires
Know the vertical change of the ...