​Optimism is a positive attribute until it descends into delusion.

Those who believe that the earth can sustain an indefinite increase in human population have taken the plunge. Rather than confront the obvious negative consequences of burgeoning human population with anything approaching reasonable concern and objective logic, these buoyant optimists float above reality on hopes that human ingenuity will find a way to pack more people onto the planet.

These people-packers are often the same folks who dismiss global warming as an agenda-driven fabrication of hysterical environmentalists, or who argue that a certain amount of environmental damage is inevitable and necessary for the advancement of human civilization.

The critical concept here is “certain amount.”

By now, the list of environmental ravages caused by human activity is not only familiar to anyone who hasn’t been in a coma the last 50 years, but is also growing with each additional mouth to be fed, thirst to be slaked, house to be built, fuel to be burned, and effluvia to, somehow, be disposed of.

Ironically, these troubling environmental ravages are the noxious side effects of the very human ingenuity that the people-packers believe will enable human population to increase indefinitely. But, when does a “certain amount” of environmental degradation become too much, jeopardizing human civilization by irreversibly damaging the entire ecosystem?

How much is too much?

Human population quadrupled to more than 6 billion during the last century. Estimates are it will reach 9 billion by 2050 and mushroom past 11 billion by century’s end.

And, while Malthusian predictions of a population bomb exploding have not come to pass ... yet, is it because no bomb exists or because the detonator clock is still ticking? Optimists seem to believe no population bomb will ever go off. Such optimism is like falling from a precipice and thinking all the way down, “so far so good.”

Already, there are a billion people on the planet who are malnourished. Yet, to feed the projected increase in human population, as much food will have to be produced over the next 50 years as has been consumed over the entirety of human history.

But, people-packers aren’t alarmed. They believe that the magic wand of human ingenuity will provide for all. Even if it could provide enough essential resources for billions more humans, however, how will it do so without further damaging the ability of the planet to support life as we know it?

So far, efforts to accommodate more population have had those nagging negative — and often unexpected — environmental consequences.

For instance, pouring chemical fertilizers on crops to increase yields has polluted fresh water and oceans with nitrogen runoff, as well as emitting greenhouse gases into the atmosphere. Clearing large areas of the Amazon rainforest for farmland not only diminishes the life-essential carbon/oxygen exchange, it also threatens water supplies to Brazil’s teeming urban areas.

And, while genetically engineered plants might be developed to minimize the need for artificial fertilizers, crop yields — especially grains — will be diminished by the worsening effects of climate change as increasing populations striving for greater levels of affluence further tax the environment.

Even if infinite numbers of people could be sustained without negatively altering the environment, what is so appealing about people crowding the planet like ants seething over a candy apple? Why wasn’t 2 billion, 4 billion or even 6 billion people enough? Why do the proponents of population growth want to pack ever more people onto a finite planet?

The argument for unlimited population growth is usually based on selfishly shortsighted economic interests or misguided religious beliefs.

People-packers assert that economic vitality requires ever increasing demand without which there will be economic collapse and massive unemployment. If that were true, at any point in time an economy would be deteriorating.

Economies are always unpredictable but they are also scalable and adjust with population levels. But, because it is easier to compete in an expanding market, and because human greed knows no bounds, sellers always want more demand.

The religious rationale for packing more people on the planet is that God wants more souls — you know, “be fruit flies and multiply.” Therefore, efforts to limit births are against God’s will. There is little concern about damaging the planet with population because the planet is disposable and God has room for everyone somewhere in eternity.

Whatever delusions drive people-packers, they present a global existential risk. Every space has a capacity limit. Unless this planet can be magically expanded, there will not be enough physical space, let alone essential resources, to sustain an indefinitely increasing population.

Isn’t it more humane and eminently wiser to bring population to a safe, comfortably sustainable level well before living conditions become hellish and the Malthusian bomb does explode?

— Randy Alcorn is a Santa Barbara political observer. Contact him at .(JavaScript must be enabled to view this email address) , or click here to read previous columns. The opinions expressed are his own.