On the “moral universal” proposal of Marcelo Gleiser

Marcelo Gleiser´s post on NPR 13.1 named “Beyond The Science-Religion Debate: A Spiritual Ecology?”, proposes  a way out of the polarized debate between Science and Religion. He believes that an answer to that is the development of a universal moral based on the value of life. That way he thinks one could overcome the poles of Science and Religion each one with its on understanding of the value (or lack of value) of life.
Starting by the fear of death, Gleiser believes that a healthy living (human) being would not desire death. So, based on that we should acknowledge the value of be a living being and protect life, any form of life, because we are interconnected with all life forms in our planet Earth. The preservation of life becomes, to him, in his “moral universal”.
This “moral universal” makes all living beings sacred and united by a “spiritual ecology”.
Although I think I understand his concerns I also agree that we must think of our role in our planet and that we must strive to find a rational justification that help us to act aiming the greater good of humanity and nature, I can not help seeing in his proposal a certain degree of philosophical naïveté.
If we think only in the practical consequences of the idea, we can have a glimpse of how complicated it is. Think about the idea that “we must act to preserve all life forms”. How do we preserve the life of cattle who feed millions of human beings all around the world? And all the chicken? Waht about all fishes that  are consumed every single day? And the eggs, sheep, birds, reptiles, insects, etc.?
Should all humanity become vegetarian?  But then what about the life of the plants? All the fruits, vegetables? What do we do with the lettuce´s ald tomatos´s life?
How do we preserve life without unbalancing nature itself?
And what about the situation of facing the very irrationality of human beings? If my own life is threatened in a criminal situation or if my house or my country is invaded by another people who are interested on our land and possessions and are ready to kill us all, should we lay down our lives?
Should a fireman preserve is own life instead of saving somebody else´s life or must he or her save the other person´s life offering his own instead?
I think the problem faced by Gleiser is really huge, philosophically speaking. And admire his courage of making a proposal. But I think the problem is so big that the way he proposes is limited to a choice, it does not make a concept of itself. It is in my opinion the same problem faced by Sam Harris when he affirms that science can answer moral questions based on his “choice” of the concept of “well being”.
One cannot ground a moral value in a scientific fact, because facts and values are different kind of concepts, they belong to different conceptual dimensions.
We can propose “the preservation of life” or “well being” as parameters to a moral behavior, but they are not enough to become a rational grounding to a universal moral.