Most of America may think of Maine as quaint, even rustic. Certainly not a trailblazer. Pine trees don’t make great innovators.

But here’s an area in which Maine may be setting a trend. Population. Worldwide.

Conventional wisdom is that the earth is lurching into a future of too-damned-many people. But Maine is coping with a decline in the “natural” population as more people each year die in Maine than are born. Only people moving in keep Maine growing, but barely. The United Nations projects a world population in 2050 of 9.8 billion, up from 7.7 billion today. By 2100, the UN projects 11.2 billion people.

This conventional wisdom was launched in 1968 when Dr. Paul Ehrlich and his wife, Anne, published the “The Population Bomb.” Swollen population scares the bejesus out of most of us. How on earth (literally) can the earth feed its huddled masses? Already, nearly 25,000 people die of hunger. Every day. That’s 9.1 million a year.

What might all that population do to our environment, the very source of our wealth and sustenance? How do we generate enough energy so those billions can move into the middle class? What about water? And trash?

Energy consumption has tripled since 1950. Fossil fuels will run out, even if not soon. We Americans use twice more water than people in other developed countries, triple the use of people in undeveloped countries. We create trash at twice the rate we did in 1960, even though we recycle nearly as much trash as we threw away in 1960. As the rest of the world moves into the middle class, the consumption figures will only grow and grow.

Put against that conventional wisdom the work of two other scholars, an economist who worked 60 years ago and a political scientist at work today in Canada.

The economist was Colin Clark, a Brit who settled in Australia. He ran the numbers more than 50 years ago and calculated that the world could feed 12 billion people. There were conditions, of course. The amount of land under cultivation then would have to stay under cultivation. And the farmers would have to cultivate that land with more or less the same intensity that Danish farmers in the 1950s were working their land.

A drive through the ‘burbs shows you that farmland is disappearing. Fields that grew hay a generation ago now grow malls. Still, land is also being reclaimed for farming, and Maine is a place where lots of land could be reclaimed for farming, if only the farmers are there to work the land. Sidehill farming can support such “crops” as beef cattle and turkeys or growing “perma-culture” food, such as walnuts and peaches.

Beef, turkeys and other critters can grow on land that can’t support annual plants without massive inputs from away, usually unsustainable. There is no reason (other than short-term profit) to milk cows in Arizona, but there is every reason to milk cows in Maine where they can graze rolling hills that don’t welcome tractors and combines. If farmers can make a living at it, they will open such land to grazing or to planting perma-culture.

Darrell Bricker, a Canadian political scientist, just published “Empty Planet:  The Shock of Global Planet Decline.” In this book, he takes issue with the alarming predictions of the Ehrlichs and with the United Nations predictions.

Bricker said, “The population is probably going to peak out somewhere between 8 and 9 billion people, and then is going to start to decline. When the decline starts, it’s not going to stop for a long time.” He was interviewed on the CBC program “Day Six,” which airs at 6 a.m.Saturdays on Maine Public radio.

China and India, which have two-fifths of the world’s population, won’t grow by leaps and bounds. In fact, both are at or below zero population growth, as are 20 other countries, including America. To maintain the current population, every 10 mothers must have 21 babies. Or, 2.1 children per mom. India is at 2.1, the U.S. is at 1.9, and China is at 1.5. If the trend continues, Bricker said, “By the time we get to the end of the century, the United States and China are going to have almost approximate populations.”

Bricker says two things are leading to the coming reversal of the population bomb.

One is urbanization. “On the farm, kids are an asset, a bunch of hands that you can use to do what you need to do . . . to produce your income. When you move them to the city they become an expense . . . another mouth to feed, and people make a rational economic decision which is ‘if I’m going to live in the city I’m going to have a smaller family.’

“The other thing that happens is the lives of women change when they move from rural areas and they move to the city,” Bricker said. “They get access to education, they get together with other women and they realize that maybe there’s another way forward that’s different than their grandmother . . . had. And they may want to go into the work world.”

Japan and Australia have chosen to try to get along with ever fewer people. Most of Europe has chosen to open up to more immigration. For example, nearly 10 percent of Sweden’s 10 million people are from the Middle East. The backlash among Trumpian wall-builders is also whipping across Europe. Soon, these countries with declining birth rates will have to decide whether to nurture immigration or retrench.

But, to end on an upnote, Bricker says, “Fewer people on the globe might mean that we have a better environment.” So, if Bricker is correct, the population bomb could defuse itself before it explodes.

Bob Neal recalls his sixth-grade teacher, Mr. Matkin, saying the world could someday have too many people.  That has worried him for 68 years. He hopes Bricker is correct.