Urbanization for Population and the Planet

National Geographic recently launched its “Seven Billion Special Series“–a year-long series on global population. I hesitantly read the first article expecting more of the same old gloom and doom but “The City Solution”  offers a refreshing take on why economists and environmentalists can embrace cities.

With Earth’s population headed toward nine or ten billion, dense citites are looking more like a cure–the best hope for lifting people out of poverty without wrecking the planet, writes Robert Kunzig.

Harvard economist Edward Glaeser supports this point of view in his new book, Triumph of the City where he writes, “There’s no such thing as a poor urbanized country; there’s no such thing as a rich rural country.” Poor people flock to cities, according to Glaeser, because there is more money and cities produce more because “the absence of space between people” makes it cheaper to move goods, people, and ideas. Moreover, city dwellers tread lightly:

Their roads, sewers, and power lines are shorter. Their apartments take less energy to heat and cool…and they drive less.

The fear of urbanization has not been good for cities, countries, or for the planet. The author suggests that it is a mistake to see urbanization as evil rather than as an inevitable part of development. People (and planners) should no longer look at cities as tumors “but as concentrations of human energy…to be tapped.”


Feeding More From Less

Halloween marked a new population milestone with the birth of the seven billionth person — an idea that is scary for some but sanguine for others. Worried about the finite resources available to a growing population, there is fear among some that we are headed toward famine and starvation in a world where population exceeds the earth’s carrying capacity.

A similar concern was demonstrated by Thomas Malthus 200 years ago. Population grows exponentially, Malthus explained, while food production grows at the slower arithmetic rate. Everything else the same, starvation would be indisputable.

Everything else is not the same. Crop yield is not constant, it has increased (see chart). The United States provides a good example of how population and food production have grown in a region with a strong rule of law. While corn yield has doubled nearly every ten years over the past half century, it took the population 36 years to double. At current rates of growth, it will be the next century before population doubles again. The growth in yield for other crops, such as wheat and rice, has also exceeded population growth rates (data here). In the end we are growing more food on less land, feeding ourselves and helping to feed the world.

Adapted from Environmental Trends.


Myths About Population

Global population is believed to top 7 billion. Is this a problem? Does 7 billion people constitute “overpopulation”? Nicholas Eberstadt doesn’t think so. In today’s Washington Post, Eberstadt punctures five “myths” about global population.

The myths:

  1. The world is overpopulated.
  2. Rapid population growth keeps poor countries poor.
  3. For all its ethical problems, China’s one-child policy boosts its economy.
  4. If your population declines, your economy does too.
  5. The world will have 10 billion people by 2100.

Eberstadt’s essay underscores the principle that institutions are more important than absolute numbers.  Whether a given region or society can accommodate a given number of people is a more function of the underlying economic institutions (and technological capabilities) than the total number of people or rate of population growth.  In addition, there is every reason to believe that global population growth will slow in the coming decades, and even turn negative, as birth rates tend to decline as wealth and education improves.

Originally posted at The Volokh Conspiracy.


Don’t Buy ‘More People, More Problems’

Mary Ellen Harte and Anne Ehrlich write,“Unsustainable population levels are depleting resources and denying a decent future to our descendants. We must stop the denial.”

We are in denial for a reason. For more than 40 years, climaxing around the first Earth Day, the public has been bombarded with apocalyptic tales of disaster regarding population growth. Paul Ehrlich, for example, a Stanford professor, prominent prophet of population doom and contributor to this op-ed article, predicted in his 1968 bestseller “The Population Bomb” that millions of people would die of starvation during the 1970s because the Earth’s inhabitants would multiply at a faster rate than the world’s ability to supply food. Six years later, in “The End of Affluence,” a book he co-authored with his wife, Anne Ehrlich, the death toll estimates increased to a billion dying from starvation by the mid-1980s. By 1985, Ehrlich predicted, the world would enter a genuine era of scarcity.

Paul Ehrlich’s predicted famines never materialized. While too many people remain hungry, agricultural advances have fought off massive famines. Even as the world’s population doubled, per-capita food consumption in poor countries increased from 1,932 calories a day in 1961 to 2,650 in 1998, and malnutrition in those countries fell from 45% of the population in 1949 to about 18%. Furthermore, fertility rates dropped from about five children per woman in the 1960s to about 2.5 today.

The authors also write that “the effects of overpopulation play a part in practically every daily report of mass human calamity.” Floods, for example, “inundate more homes as populations expand into floodplains. Such extreme events are stoked by climate change, fueled by increasing carbon emissions from an expanding global population.”

These modern day predictions are in stark contrast to claims of the same vein from the 1970s. In a popular 1970 speech at Swarthmore College, for example, well-known ecologist Kenneth Watt said, “If present trends continue, the world will be about four degrees colder for the global mean temperature in 1990, but 11 degrees colder in the year 2000. This is about twice what it would take to put us into an ice age.”

Time has not been gentle with such prophecies. Four decades later, the world hasn’t come to an end. Most measures of human welfare show the Earth’s population is better off today than at any other time in human history. Life expectancy is increasing, per-capita income is rising, and the air we breathe and the water we drink are cleaner. And concerns about climate change have shifted from cooling to warming since the 1970s.

Given past trends, we are right to deny doom and gloom claims such as this one in Harte and Ehrlich’s op-ed article: “Perpetual growth is the creed of a cancer cell, not a sustainable human society.”

New ideas and technologies proliferate at a much faster rate than population. They depend on individuals who are free to pursue their own interests and innovate with few constraints. As Stanford economist Paul Romer put it, “Every generation has perceived the limits to growth that finite resources and undesirable side effects would pose if no new recipes or ideas were discovered. And every generation has underestimated the potential for finding new recipes and ideas. We consistently fail to grasp how many ideas remain to be discovered. Possibilities do not add up; they multiply.”

The trouble with the sky-is-falling claims is that they can lead to costly and restrictive government regulations and media biases. Harte and Ehrlich, for example, think the government should have a greater role in family planning and that we should “demand that media start educating the public every day on the role played by the unsustainable human numbers behind environmental degradation and human calamities.” The public, they claim, “needs a constant message: It’s time to stop growing and become sustainable.”

In truth, it’s the opposite. Such regulations and media propaganda could aid in suffocating the kind of advances that have helped improve environmental conditions and human well-being.