[extropy-chat] Panicmongering

[Damien Sullivan]

On Mon, Jun 26, 2006 at 10:53:09PM -0700, Lee Corbin wrote:
> Spike writes

> > futile.  So we need to triple our current everything.  My notion is
> > to build the newer cities on a Silicon Valley model as opposed to a
> > New York City model.  More land for everyone, less attractive as

Ugh!

> Let's see what population densities that might be. Suburbs currently 
> run at about 10,000 people per square mile, or 6000 per square
> kilometer.

Where do you get those numbers?
http://www4.wittenberg.edu/academics/urban_studies/BFINALEC.html
gives 2000 people per square mile.

Some numbers I have burned into my memory:
Manhattan 65,000
NYC 25,000
(Outer boroughs 15,000)
San Francisco 16,000
Chicago 12,000
LA 9,000
Berkeley, Pasadena 5,000 [could be wrong about Berkeley]
Dallas 3,000

http://www.perc.org/perc.php?id=374
"only half of Americans live in 2,000/mile^2 or higher" -- Indianapolis
or Tulsa densities.
18% at 5,000 or more.  1/3 at 3,000 or more.  And that's the central
cities.

I'd note that typical suburban quarter-acre lots would give 640 lots per
square mile, or less after accounting for roads, for about 2400 people
per square mile.

> but are vacant now. Food production has increased per acre by
> about a factor of 5 since 1950, while the population has only

It's not clear that's sustainable, given energy inputs to corn from
petroleum-made fertilizers comparable to the energy inputs from the sun.
Not to mention the unhealthy aspects of a corn-based diet... I just read
Michael Pollan's _The Omnivore's Dilemma_ and liked it a lot.  Looking
at where our food comes from.

> about doubled. Julian Simon writes about the marvels of hydroponics
> in "The Ultimate Resource2", and an area the size of San Antonio,
> Texas could feed the present population of the U.S.

Area of San Antonio: 1000 km^2.
Solar energy input estimate: 3e11 watts.
Energy consumed by US human bodies: 3e10 watts

You'd need 10% energy capture when plants tend to get 1%.  Okay, 8% at
the high end of algae or growing sugar cane.  Where's the beef?  Not to
mention the electricity.

> Anyway, at roughly 3,000,000 square miles, by the above reckoning
> there is room for 3,000,000 times 10,000 or about 30 billion souls

Using 3e14 watts, in an area collected 6e14 watts if you roof everything
over in solar panels.

-xx- Damien X-)