How to demonstrate the human impact on the environment?
Not that I don’t believe that we humans are contributing to global warming BUT… The environment is extremely complicated as well as works in numerous dynamic cycles that we don’t at all understand. We’ve only really been keeping good data on the climate for the last 50 years or so and just simply don’t have the data or understanding to do what you’re suggesting. The state of the earth is so dynamic that there is no natural state of where things should be, how hot it should be, how humid, how much light gets to the surface, how much ice, how many living things there are, etc. Since it is always changing, regardless of any human activity, trying to stop it or slow it, or trying to show how much we are adding to it is just too much to ask.