It is true there is a finite limit to the human population the planet can support and maintain a health [sic] biological diversity.
At some point the balance between people and the environment is going to get tipped against forests, animals and nature. Thomas Malthus was famously wrong two centuries ago when he said it was happening. Paul Ehrlich was also wrong last century.
Is 7 billion the magic number? Tough to say.
What taboo? The left has been complaining about “overpopulation” for quite some time, so it’s not surprising that it would make an appearance on the left-leaning SciGuy’s blog. Even better that a little Global Warmism is part of the mix!
Here’s the sort of perspective that one won’t ever find on SciGuy’s blog, on the other hand:
Sure, 7 billion is a big number. But most serious demographers, economists and population specialists rarely use the term “overpopulation” – because there is no clear demographic definition.
For instance, is Haiti, with an annual population growth rate of 1.3 percent, overpopulated? If it is, then was the United States overpopulated in 1790, when the new country was growing at more than 3 percent per year? And if population density is the correct yardstick, then Monaco, with more than 16,000 people per square kilometer, has a far greater problem than, say, Bangladesh and its 1,000 people per square kilometer.
Back in the 1970s, some scholars tried to estimate the “optimum population” for particular countries, but most gave up. There were too many uncertainties (how much food would the world produce with future technologies?) and too many value judgments (how much parkland is ideal?)
Even considering resource scarcity isn’t all that helpful. During the 20th century’s population explosion – when we went from 1.6 billion people to more than 6 billion – real prices for rice, corn and wheat fell radically, and despite recent spikes, real prices for food are lower than 100 years ago. Prices, of course, are meant to reflect scarcity; by such reasoning, the world would be less overpopulated today than a century ago, not more.
Eberstadt’s piece is a good read (as is most of his work).