I recently interviewed Lincoln Brower. Lincoln is the foremost scientist studying the monarch butterfly. Both Lincoln and the butterfly are rare creatures.

I don’t know what Lincoln weighs, but the monarch weighs about 1/10 of an ounce. You could mail ten of them from Minnesota to Texas for 34 cents if you could get them to stay in an envelope.

They are remarkable because they make this trip or more each year on their own four wings. Each fall, as the northern growing season begins to slow down, the monarchs head for their winter home in Mexico.

Their parents have traveled north in late spring in pursuit of their food plant, the milkweed. As milkweeds appear in each latitude in the U.S., so do the monarchs. They lay their eggs, the caterpillars emerge, they feed for a few weeks on the milkweed leaves, and then they form a chrysalis to make the transformation into a butterfly.

When the butterfly emerges about twelve days later, he or she looks around. If it is still early enough, his or her mind is on producing another generation. If it is late, then it is time to make for Mexico.

The journey takes about six weeks from the northern latitudes of the U.S. In the beginning, individuals fly by themselves. If you look up high in the sky during the peak migration in the north, you can see one going past every minute or more. The journey south is all the more remarkable because the individuals who are retracing the steps of the northern migrants are not the same ones.

At night they seem to cluster together, hanging on tree limbs, usually near the flowers on which they have fed.

As they continue south, the individuals link up with others, so that they form what you might almost see as a cloud. At the peak, the migration is a river of these little creatures.

Their destination was unknown until discovered in the 1970’s. It is several specific locations in the mountains of a small area of Mexico, where they find the Oyamel Fir tree at an elevation of about 10,000 feet.

Here on a few acres, millions of monarchs spend the winter. Here Lincoln Brower has been coming to study these butterflies for about 30 years. And here it is that there is a problem.

The problem is this. There are too many people.

Some might argue that the problem is otherwise; that it is the fact that the people are cutting the forest where the monarchs live, or that it is the government that fails to protect this forest, or it is the fact that the sawmills consume ever more logs to make their particle board.

In the end, it is the story that is happening all over the planet. Each year there are more people competing for the same scarce resources.

When I interviewed Lincoln, it was not the butterflies that left the enduring image with me, but his vivid description of the old forests that surrounded his home town in central New Jersey during his childhood. As he talked, I could see the old trees and the young Lincoln looking up the huge trunks, looking toward the sky in search of butterflies.

Houses have replaced those trees now. Where the trees formed their forests, now houses form new communities. More people every year. More traffic, higher prices, more crowding, fewer resources.

There were 150 million people in the U.S. when I was a student. Now we are approaching 300 million.

Worldwide, the population has passed 6 billion. There are 1 million more every 5 days, or 70 million each year.

The United States was once a positive influence in birth control issues, through direct aid and through the United Nations. Now, for religious reasons, our Congress is caught up in arguing about the rights of the “unborn”. Our birth control programs have been stripped or eliminated. Our wild species are disappearing because old men argue about a few cells that are at a stage that none of them could distinguish from an unborn fish.

It’s OK to let tigers disappear from the planet. Chimpanzees aren’t important. Who cares about songbirds?

But try to divorce a single human sperm from its target egg and you’ve committed a sin something you will rot in Hell for.

This would be laughable if it didn’t mean the disappearance of so much of our natural land and animals. If it didn’t mean that houses will soon be so expensive that most people will live in stacked cubes.

Population is at the root of every environmental issue. Cut the population in half, and half the pollutants disappear, without changing the behavior of a single person.

Population and birth control are key elements in the fight against poverty and crime. Lower populations mean fewer people competing for the same housing. Smaller family size or older first parents mean more stability at home, more resources for the individual child.

It is deplorable that Planned Parenthood, the only organization that has much affect on birth control here in the U.S., is vilified by the old men who argue for the rights of the “unborn”. It is sickening that doctors have been murdered by the disciples of these old men.

Doing something about population starts at home. Two children per family creates a stable population. Three children per family means a fast growing population.

The actual number is more like 2.1 children per family, since, for a variety of reasons, some children will not reproduce.

If you have more than two children, it’s been done and it shouldn’t be on anyone’s conscience. What is important now is to let our children know what they need to do to make a difference.

And if you care about open space, about birds or butterflies or trees, take a look at what the organizations you support are doing. Is your church fighting for the rights of the “unborn”? Does your party advocate funding birth control?

If you don’t care about the natural world, then look at it this way. One of the important characteristics of population dynamics is that populations often collapse. Growing beyond the carrying capacity is one of the key factors that causes a collapse. Famine and disease can spread quickly when the conditions are right.

It is the tiny animals, those that start at the monarch’s size and go on down, that are the fabric upon which food chains are built. Destroy the soil microbes and a lot of bad things happen.

Whether we love nature or hate it, we are dependant upon its success. At the moment, it is not succeeding. Humans are doing a very good job at killing it.

The problem is simple -- there are too many people.