The format of the diagram and analysis above is classical electronics and Servo Systems theory. There are millions of such sytems in use throughout the industrial world even though such things are generally less than a century old.
There is also a multitude of systems in nature which regulate how the atmosphere and the whole of the world's biota operate. There are very few things which are not amenable to description in feedback terms.
Both man-made and natural feedback systems tend to to be very powerful and very useful. One has to be careful that the feedback is actually negative. In practice most systems involve time and that can cause feedback signals to 'get out of sync'. This usually leads to a disaster. The feedback that becomes positive boosts the output to the point that the only restriction is the availability of energy. That can be quite massive, especially in natural systems.
This is why Global Warming is so scary. There are many feedback systems which control the temperature and many other parameters of the atmosphere and biosphere and if one of them 'goes positive' then it will be virtually unstoppable.
