Why aren't we able to change our global environmental behavior in spite of the consequences?
We humans are social beings. We like to be part of a group of people that are behaving in the same way and have more or less the same values. And I think this is part of the root cause of all the environmental issues we see today.
In the 20th and 21st century we have gained enormous power fueled by fossil energy to shape the environment to our greatest comfort. Along with that we have gradually lost leaders in our society with highly developed consciousnesses and a deep understanding of our human nature (or psyche, psychology). What we now know about human psychology is far more impractical than the insights gained by deep and thorough introspection. The kind of introspection that you can only achieve through regular and long-lasting concentration on the present moment. Serious meditation is today practiced only by a small minority of people.
We lack to understand our own psyche on a global scale. Therefore we missed the opportunity to use the outcomes of our gain in scientific understanding in our favor. This can be seen directly if one compares western societies to the traditional middle eastern societies. Communities, still grounding their behavior on the active exploration of the human psyche, have a far greater understanding of how outer circumstances lead to inner happiness. Their way of life, sustainable intertwined with natures processes, lead to happiness without all the inefficiencies and destructive outcomes of "modern" western societies.Why is it than difficult for people to behave in an environmentally sustainable way, in spite of understanding the consequences?
It is difficult because of our underdeveloped understanding of mind and psyche. Most people today are in a fragile psychological state. And in my experience this becomes only obvious after you have had some "enlightenment" experiences in the context of exploring your inner psyche with meditation. And it is therefore difficult to convey to people without such insight. But being in such a fragile (childish) state, every action taken serves the purpose of increasing feelings of well being and social integration. Even little tragedy can produce great fear and unhappiness. Many people have basically zero happiness routed in their own being. Clinging to the outer world and seeking for happiness outside of ones own mind. Lack of even the most basic understanding of the mind (e.g. that happiness is a product of the mind) leaves the human population without direction and desperate on the search for happiness in places it cannot be found.
Coming back to the original hypothesis. The feeling of social integration is what produces a high degree of safety and comfort. Being part of a larger group of people and mimicking their behavior is what covers the feeling of being lost.
Therefore we are unwilling of change to an environmentally sustainable way of living on a broader scale. Fear of being different and loosing this comforting behavior is what keeps people unconsciously from changing. On the conscious surface this is explained with rational arguments. But ultimately they are all grounded in a deep existential fear. And that is, as I already explained, coming from a lack of understanding our human nature.In order to conserve our the natural environment we therefore must begin with clearing the fog inside our global consciousness. This starts with individuals exploring and understanding our inner psychological workings and teaching and spreading this way to other beings.