When it became obvious to the president that HealthCare.gov was a disaster -- several days after it launched, reportedly -- he knew just what to do: Hire more people to work on the site.

"To ensure that we make swift progress, and that the consumer experience continues to improve, our team has called in additional help to solve some of the more complex technical issues we are encountering," the Health and Human Services Department announced on October 20.

The problems with Obamacare run far deeper than the website. But the government's approach to this particular problem is the correct one: As a general rule, people solve problems. Even seemingly unsolvable problems tumble before human ingenuity.

Take oil. It's a finite resource; they're not making any more. In the 1950s, oil-industry expert M. King Hubbert predicted the U.S. would reach "peak oil" production around 1970. After that it would be all downhill. And for decades, he seemed to be correct. The U.S. would be a net importer forever, sending valuable dollars overseas for crude oil.

But hold on. "The United States has overtaken Saudi Arabia to become the world's biggest oil producer," Reuters reports, "as the jump in output from shale plays has led to the second biggest oil boom in history."

We're not at 1970 levels yet, but we're on a marked upswing. How did this happen? Hydraulic fracturing, developed by humans to get oil out of tight rock formations. And horizontal drilling, to allow for exploration across vast areas with a relatively tiny footprint. Humans saw a problem. Humans solved a problem.

That's not how everybody sees it. Some still warn that a "population boom" is putting Earth itself at risk.

For example, worrywart Alan Weisman is out with a new book, Countdown, about the danger of overpopulation. "Everywhere he goes, Weisman reports on the problems that fast-rising populations have created: rivers running dry, coral reefs without fish, disappearing forests, changing climates and eroding soils," writes Fred Pearce in his Washington Post review. "But defusing the population bomb gives us a shot at cleaning up the mess."

Of course, humans are already solving some of those problems. We're creating marine reserves to protect reefs. Huge parts of the U.S. have been reforested since we stopped using wood for fuel. Where once we cut down trees indiscriminately and killed whales for their oil, we now grow more trees than we cut down and protect whales.

Humans also want to keep rivers flowing and soil from eroding. And we will. As long as there are enough of us alive to do so. But Weisman warns that there are too darn many of us already, and that's distracting us.

"An educated woman has an interesting and useful contribution to make to her family and her society," he writes at CNN.com. "Since she can't easily do that with seven children hanging on her skirts, most women who get through secondary school want two children or fewer. Providing access to contraception and educating women may be the fastest path to giving our planet a break."

But like "peak oil," overpopulation is an idea that should have gone out of style. The concern these days, as David Goldman explains in his book How Civilizations Die, is underpopulation.

The United States is the only large industrialized country with a birthrate above the replacement level (2.1 children per woman). Populations in the rest of the developed world, from Europe to Japan, are shrinking. The same thing is happening in the Middle East. "Muslim countries with a high literacy rate -- Iran, Turkey, Algeria, Tunisia -- have already fallen below replacement fertility," Goldman says. "Most Iranians have six siblings, but will have one or two children."This sort of depopulation has never happened before. Goldman warns that it could mean more violence, as Islamic nations realize they have no future. It will, at a minimum, mean we must radically reform our entitlement systems or see them collapse across the developed world, as workers will simply be unable to afford all the benefits promised to older generations.

Neither of those developments would be positive. But at least there will be fewer people around to suffer through them. Humanity has already solved overpopulation. Let's see if we're clever enough to deal with underpopulation.

 - Rich Tucker is senior writer in the B. Kenneth Simon Center for Principles and Politics at the Heritage Foundation.