" primitive societies sustained themselves for thousands of years, using only survival instinct and faith in their gods. Our present society is heading for destruction, despite, or perhaps because of our vastly superior knowledge of science."

Primitive societies existed (and still do here and there) because they understand that human beings are part of the natural world, a part of an ecosystem that they need to respect and sustain in order to survive; a way of living that runs contrary to the teachings of the Abrahamic religions, which says:

"And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth."

This nasty, ignorant and downright evil little tract absolves those with less integrity and gumption than normal of the responsibility of caring for the earth: "God says it was alright". Of course, the fact we're all brought up and raised largely as Christians/Muslims/Jews of some sort means that this point of view is entrenched in our culture; that has nothing to do with science.

"Perhaps we would have a healthier planet without science?"

Science is a system for discovering the fundamental truth of the nature of things, and it seeks to understand and enlighten. How that knowledge is used is a social question rather than a scientific one, and responsibility for forming policy based on science and establish commercial value to the results of scientific discovery is the realm of politicians, business people and the rest of us (although inequality robs most of us of any meaningful influence over policy and business).

As scientists we know the planet is in deep trouble as we are living through a mass extinction of catastrophic proportions, climate change is probably not going to be stopped and we are polluting our seas and clearing them of fish at a rate that means the oceans are fundamentally changing in nature (which is more frightening than the melting of the ice caps by some degree). Science isn't responsible for this because it advances technology; this situation has arisen because of an unsustainable economic system and politicians and big business taking advantage of their position. It's their lack of responsibility that will kill millions in the Bangladesh delta and the deserts of Africa, not scientists.

"which by its very nature is not subject to the scientific method of observation, testability, repeatability except in a much more limited sense.

Boring. The defining characteristic of science is that it is testable and falsifiable, and evolutionary theory certainly comes into this, as do many, many other aspects of science such as astrophysics and pure maths (no-one has ever directly observed the gas giant Kepler-87b orbiting it's home star, but we know it's there, know it's mass and its orbital period - about 114 days). But even though observation and repeatability do of course play a role in science, it seems that creationists do not apply these techniques to their own beliefs: creationist dogma crumbles if you try to observe it in action, it can't be repeated and it is not testable in the slightest. The maker remains conspicuous by their absence.