Americans are spending more and more time sitting in their cars going nowhere as freeways and streets become, in effect, parking lots.

Population growth is the ever-expanding denominator that gives each person a shrinking share of the resource pie.

It contributes to water shortages, cropland conversion to non-farm uses, traffic congestion, more garbage, over-fishing, crowding in national parks, a growing dependence on imported oil and other conditions that diminish the quality of our daily lives.

Expanding exponentially

With births exceeding deaths by nearly two to one, the U.S. population grows by almost 1.8 million each year — or 0.6%. Adding nearly one million immigrants per year brings the annual growth rate up to 0.9%, raising the total addition to 2.7 million. As things now stand, the United States is headed for 400 million people by 2043.

U.S. population growth contrasts with the situation in other industrial countries such as France, the United Kingdom, Germany, Italy and Japan, where populations are either essentially stable or declining slightly. In virtually every industrial society where women are well-educated and have ready access to jobs, they have on average two children or fewer.

Draining resources

More people require more of everything, including water.

Population growth is the ever-expanding denominator that gives each person a shrinking share of the resource pie.

In our highly urbanized society, we fail to recognize how much water one person uses.

While we drink close to a gallon of water each day as water, juice, pop, coffee, tea, beer or wine, it takes some 500 gallons a day to produce the food we consume.

The U.S. annual population growth of nearly three million contributes to the water shortages that are plaguing the western half of the country and many areas in the East as well.

In hot water

Water tables are now falling throughout most of the Great Plains and in the U.S. Southwest. Lakes are disappearing and rivers are running dry. It has been years since the Colorado River, the largest river in the U.S. Southwest, reached the Gulf of Mexico.

As water supplies tighten, the competition between farmers and cities intensifies. In this contest, farmers almost always lose. Scarcely a day goes by in the western United States without another farmer or an entire irrigation district selling their water rights to cities like Denver, Las Vegas, Phoenix, Los Angeles or San Diego.

The seafood appetite of 300 million Americans is also outgrowing the sustainable yield of its coastal fisheries. Long-time seafood staples such as cod off the New England coast, red snapper in the Gulf of Mexico and salmon in the U.S. Northwest are threatened by over fishing.

Car craze

In the United States, more people means more cars. And that in turn means paving more land for roads and parking lots.

As things now stand, the United States is headed for 400 million people by 2043.

Each U.S. car requires nearly one-fifth of an acre of paved land for roads and parking space.

For every five cars added to the U.S. fleet, an area the size of a football field is covered with asphalt. More often than not, this land being paved is cropland simply because the flat, well-drained soils that are good for farming are also ideal for building roads and parking lots.

Losing land

Once paved, land is not easily reclaimed. As environmentalist Rupert Cutler once noted, "Asphalt is the land’s last crop."

The United States, with its 226 million motor vehicles, has paved some four million miles of road — enough to circle the Earth at the equator 157 times. In addition to roads, cars require parking space.

One giant parking lot

Imagine a parking lot for 226 million cars and trucks.

Scarcely a day goes by without another farmer or an entire irrigation district selling their water rights to cities like Denver, Las Vegas, Phoenix, Los Angeles or San Diego.

If that is too difficult, try visualizing a parking lot for 1,000 cars and then imagine what 226,000 of these would look like.

More cars also translates into more traffic congestion. Americans are spending more and more time sitting in their cars going nowhere as freeways and streets become, in effect, parking lots. As cities sprawl, commuter distance lengthens.

Longer commuting distances and more congestion en route combine to increase the time spent in automobiles. In 1982 the average motorist experienced 16 hours of delay. By 2003 this had virtually tripled to 47 hours.

Rush hour

Car commuting time is increasing in nearly every U.S. metropolitan area. "Rush hour" everywhere is becoming longer as commuters attempt to beat it by leaving work early or delaying their commute until traffic eventually wanes.

The costs of increasing congestion and longer commuting times are high. Traffic congestion in the United States in 2003 caused 3.7 billion hours of travel delay and wasted 2.3 billion gallons of fuel. The total bill for all of this was $63 billion.

Gorging getaways

More people mean that not only are our home towns

It has been years since the Colorado River, the largest river in the U.S. Southwest, reached the Gulf of Mexico.

more crowded, but so too are the "get away" spots where we go for relaxation. National parks, wilderness areas and beaches are seeing more visitors each year. U.S. national parks sometimes have to turn tourists away.

In 1906, when Yosemite National Park was young and when we were a far less mobile population, the park had 5,000 visitors. Today, more than three million people — and their cars — visit the park each year.

Loading landfills

More people also usually means more garbage. New York City, for example, generates 12,000 tons of garbage a day, a flow that requires 600 tractor-trailers — fully loaded — to leave the city each day headed for remote landfills in New Jersey, Pennsylvania, Virginia and Ohio.

Trucking garbage to ever more distant landfills makes us more dependent on distant sources of oil. As population grows, so does energy consumption. The United States, richly endowed with oil, has largely depleted its petroleum reserves within two generations.

Oil dependence

The use of oil has exceeded new discoveries in the United States for some 25 years. As reserves shrink, U.S. production falls and imports climb, helping to drive up world oil prices.

In 1906, Yosemite National Park had 5,000 visitors. Today, more than three million people — and their cars — visit the park each year.

And as population increases, so do the emissions of the Earth-warming gas carbon dioxide.

Given the negative effects of continuing population growth on our daily lives, it may be time to establish a national population policy, one that would lead toward population stabilization sooner rather than later.