Up until this point businesses were unregulated and free. After all, if employees were unhappy with their working conditions they were free to make a living off of the land. But once there was no longer available land free for the taking, people no longer had a choice and had to accept whatever employment they could find. It became necessary to put regulations on businesses in order to protect the right to life of the people. For example, employers could not discriminate against their employees if their employees were going to be able to find employment and so be able to live. The right to liberty of the business owner was sacrificed in order to protect the right to life of the people. Government food assistance programs also became necessary to protect the right to life since people were no longer able to provide for themselves through working the land.
To take another example, originally, people and businesses were able to dump their waste into the rivers and air. After all, a person living in relatively isolation can not produce enough waste to affect the rights of other people. However, with population growth enough pollution will soon be being dumped into the water and air that it will begin to affect the health of others. As in the first case, the response will be to limit the rights of some in order to protect the rights of others and to establish new government powers in order to achieve this. Pollution laws come into affect to make sure that the air and water is not being polluted as to harm the health of others. Similarly, eminent domain laws can be used to seize people’s property in order to provide drinking water for growing populations as was done in Massachusetts with the creation of Quabbin reservoir. Here again property rights were sacrificed for others right to health.
Science fiction writers have considered cases where overpopulation and environmental degradation becomes so severe that even the right to life of some is sacrificed to protect the life of others. Thankfully we have not yet reached this point.
All of these examples are the similar in that environmental destruction causes restrictions on the rights to property and liberty. And this is something that Libertarians do not understand, that freedom is an adaptation to environmental conditions. Perfect freedom can only exist in a relatively low population density with many available resources for the sustenance of life. As Hume writes:
Let us suppose, that nature has bestowed on the human race such profuse abundance of all external conveniencies, that, without any uncertainty in the event, without any care or industry on our part, every individual finds himself fully provided with whatever his most voracious appetites can want…
It seems evident, that, in such a happy state, every other social virtue would flourish, and receive tenfold encrease; but the cautious, jealous virtue of justice would never once have been dreamed of. For what purpose make a partition of goods, where everyone has already more than enough? Why give rise to property where there cannot possibly be any injury?
…
We see, even in the present necessitous condition of mankind, that, wherever any benefit is bestowed by nature in an unlimited abundance, we leave it always in common among the whole human race, and make no subdivisions of right and property. Water and air, though the most necessary of all objects, are not challenged as the property of individuals; nor can any man commit injustice by the most lavish use and enjoyment of these blessings.
…
Thus, the rules of equity or justice depend entirely on the particular state and condition, in which men are placed (An Enquiry Concerning the Principles of Morals.)
Of course the irony is that, impossible though it was for Hume to see, air and water now can be the subject of injustice and that we do now possess the capability to foul the air and water sufficiently that their use and misuse can be brought under the purview of justice. But in all cases environmental destruction is the enemy of liberty, not the restrictions that attempt to protect people's rights as far as possible, and in all cases libertarians would best serve their desire for freedom by preventing the environmental conditions that require ever greater extension of the jealous virtue of justice.