The answer to all these questions is a rather simple one:
In our technology and scientific minded world, we seem to have forgotten that mankind is only a relatively minor part of Nature. We ignore being part of a larger whole.
We believe to be able to control Nature instead of trying to arrange ourselves with Nature. This haughtiness is the true main cause of global warming. As a matter of fact, some people still believe that technical solutions alone would be sufficient to fight global warming.
Although we are guests on Earth, we behave as if no further visitors would arrive after us. It's like having a wild party where we destroy beds, the kitchen as well as the living room of a hotel without ever thinking about our future staying in the hotel nor about other guests arriving later.