"natural constraints" is an acceptable and usable phrase in written English.
You can use it when you want to refer to limitations or obstacles that are due to physical or environmental factors rather than manmade ones. For example, "The natural constraints of the environment meant that we had to find a new way to reach our destination."
Any additional constraint naturally creates complications, but we expect that at least a few natural constraints can be handled within the framework described here.
Looking closely at the most characteristic themes in his work (for instance, the epistemological, and hence ontological, unity of the individual, or the freedom of the human will, which enables the wise man to overcome natural constraints by means of virtue), it is clear that both his naturalism and empiricism need to be seen against the background of the divine government of the world.
Both extreme positions ignore the more complex reality that human choices interact with natural constraints.
Markets with strict planning controls or natural constraints on building are much more prone to booms and bust.
The problem is not just the number of mouths to feed; it's the quantity of food that each mouth consumes when there are no natural constraints.
Who lives where will depend on public policy (zoning rules, petrol taxes, etc), on natural constraints (water, energy) and on individual tastes.
Utilitarianism is a natural constraint, an allegedly single naturally correct way for all of us to choose our course.
The torpedo shape probably reflects a natural constraint on the heart's growth, Wood said.
There isn't a natural constraint on public-sector wages and benefits in the same way.
Scientists generally think there is a natural constraint, the Hayflick limit, on how many times such cells can divide in tissue culture before they decay and die.
According to a report by the American Health Insurance Plans, these out-of-network fees can be exorbitantly high, which serves as a natural constraint on the free choice of provider under P.P.O.'s.
