There's a portion of the liberal crowd that believes that there are too many people in the world and what would be best for Mother Earth and the environment is a drastic reduction in the number of people who exist. In more simplistic terms, people are bad. No doubt given the opportunity to decide whom to remove from the planet, conservatives would be their first targets.
Unfortunately, now they have some opinion, masquerading as authoritative science behind them in the form of a book called Countdown by Alan Weisman.
It sounds like time to panic.
The New York Times was quick to jump on board the panic wagon;
As Alan Weisman’s “Countdown” amply demonstrates, we are well on our way. Some seven billion people are alive today; the United Nations estimates that by the end of the century we could number as many as 15.8 billion. Biologists have calculated that an ideal population — the number at which everyone could live at a first-world level of consumption, without ruining the planet irretrievably — would be 1.5 billion.Weisman’s jeremiad amounts to a world tour of our overpopulation misery. He begins in Jerusalem, where he learns that construction firms worry about running out of sand, despite the fact that half of Israel is a desert. Water is in short supply, too. Because of agricultural irrigation, the Jordan River is now a “fetid ditch”; pilgrims who attempt to bathe at the spot where Jesus is said to have been baptized will develop a rash and, if they swallow the water, will most likely vomit.
If that's not bulletproof evidence I don't know what would be. A fetid ditch? Oh my. If you asked biologists 100 years ago about sustainable population, before all of the advances in efficiencies farming and irrigation and I'm sure they have argued a number well below 1 billion. And yet here we are, 7 billion strong. What's lacking is not more resources for sustainability but the thought of the boundless possibilities for mankind. Improved desalinization, better farming, space travel and colonization, terraforming and who knows what else. All of those things may one day make resource scarcity a thing of the past. Ask a virus if it's worried about there being too much of itself. Ask a mosquito or a rabbit. If they could answer it would be in the form of a laugh.
If indeed we are on a path to too many people, the human population will be naturally self-regulated by the availability of resources. What we don't need is a population alarmist worrying about a Malthusian crisis and scaring us all back into the 5th century B.C. There are far too many people alive who will believe that silliness.