April 26, 2004

That's A Lot Of Footprints

From The Future of Life (2002), by Harvard professor Edward O. Wilson, a "leading voice for the preservation of biodiversity and the founder of a field of study relating social behavior to genetic advantage."

Consider that with the global population past six billion and on its way to eight billion or more by midcentury, per capita freshwater and arable land are descending to levels resource experts agree are risky. The ecological footprint-the average amount of productive land and shallow sea appropriated by each person in bits and pieces from around the world for food, water, housing, energy, transportation, commerce, and waste absorption - is about one hectare (2.5 acres) in developing nations but about 9.6 hectares (24 acres) in the U.S. The footprint for the total human population is 2.1 hectares (5.2 acres)

There are about 291 million people in the US, according to the census bureau.

291 milllion people @ 24 acres each is 6,984,000,000 acres

640 acres in a square mile = 10.9 million square miles. That is more than the total area of the US, Canada and Brazil combined, including bodies of water, deserts, mountains, rain forests, tundra, high arctic....

Now, taking Dr.Wilson's estimate that the rest of the world's population of averages a "footprint" of 5.2 acres each...

and there are over 5.7 billion of them...

That's an additional 29.6 billion acres, or 46.3 million square miles.

Total dry land on the planet? 57.5 million miles. 4.5 million of that is in Antarctica.

His bio does offer this disclaimer;

[Dr. Wilson] has received numerous awards, including the National Medal of Science awarded by President Jimmy Carter and the Craaford Prize issued by the Royal Swedish Academy of Sciences. His confidence with words and his love of nature enabled two Pulitzer Prizes, one for On Human Nature and the other for The Ants. Writing comes easy to him, far easier than mathematics.


It gets worse... the FAO estimates that 5.6 million square miles of this is arable land.

If the rest of the world's human "footprint" already uses 900% of the world's arable land - where the hell are the Americans getting theirs?

hat tip - Dad

Added to the Beltway Traffic Jam

Posted by Kate at April 26, 2004 2:05 AM

Bravo, Kate! Too many famous people get away with making apocalyptic statements like Wilson's, because too few so-called journalists are too willing to accept what they say at face value instead of saying, "Hey, wait, the emperor has no clothes!"

Posted by: Frank at April 26, 2004 3:39 AM

It doesn't change your qualitative results, but you transposed the 2.5 to 5.2. The 5.7 billion need 22.3 million additonal
square miles, and the rest of the world's ``footprint'' accounts
for 400% of the arable land.

Posted by: Christopher Basten at April 26, 2004 10:07 AM

No, the 5.2 comes from later in the quote.

Thanks for bringing it up, I've added the extra sentence to the quote to clear that up.

Posted by: Kate at April 26, 2004 10:44 AM

I'm not sure what "shallow sea" is, exactly, but it apparently is something other than land. Still, his numbers don't make any sense.

Posted by: James Joyner at April 26, 2004 5:31 PM

If I've understood correctly, the per-person "footprint" is denominated in land required for all purposes, not just in arable land, i.e. land suitable for agriculture. Unless I've overlooked it in my quick scan of this post, an estimate of the amount of arable land required per person is never stated. Dr. Wilson's numbers would only be absurd if he had offered an estimate of the amount of ARABLE land required per person that, when extended over the entire population, exceeded the amount of arable land available.

Posted by: Doug at April 26, 2004 9:34 PM

Stop nitpicking.

Posted by: Kate at April 26, 2004 9:48 PM

Actually, the 5.2 is (from what you quote) the average of everyone including the US. Since the US footprint is higher, you'd need to factor it out.

Note that the 2.5 is only developing countries, so wouldn't a host of places.

Taking US population at .3 billion, and world at 5.7, you have, the rest of the world would be ca. 4.96 hectares/person (of course, this assumes the numbers aren't simply made up).

Posted by: Craig at April 27, 2004 8:19 AM

Ecological Footprints ? Old and bad idea.
Two main reasons :
1) They're including everything, including the land that you need to recycle your CO2 emissions.
2) Land can be used for more than one purpose. The land which is used to grow my food is also at the same time recycling your CO2 emissions and could quite possibly be recycling the crap coming out of the cow that someone else ate last week.
So even if it were true that x acres needs to be used to support each human, we can't add these up : the same acre can be used by different people for different things simoultaneously.

Posted by: Tim Worstall at April 27, 2004 8:21 AM

The reason I didn't bother "factoring out" the US population from the average or worrying about what portion arable land... yada yada ... is that the entire premise fails.

That the figures he gives for his "footprints" take up virtually all the dry land on the planet is about all you need to know that you can discount them. At that point further factoring is irrelevant and a waste of time. Youre basing your calculations on worthless information.

Posted by: Kate at April 27, 2004 10:13 AM

I remember encountering E.O. Wilson long ago when I was working on my biology & chemistry degrees in college. His basic premise, in brief, was that moral traits such as altruism conferred an evolutionary advantage and thus had some sort of genetic basis. Maybe that's true, but the brute reductionism of it all just really grated on me, and still does.

Every day we're faced with the constant litany than we're nothing more than the sum of our respective parts, and Wilson is one more contributor to that tiresome theme.

Posted by: Curt at April 27, 2004 1:29 PM

Tim is correct. The "ecological footprint" is an ideological fiction created to beat up westerners over their "immoral", "excessive" lifestyles.

Most of the footprint, IIRC, consists of land required to absorb CO2 generated by human activity (ironically, this calculation has the happy effect of giving nuclear power--by far the most hated energy technology out there--the smallest footprint of all). As Tim points out, it ignores dual-use land, and more importantly, ignores the enormous CO2-sinking capacity of the ocean.

There are a host of other objections to the footprint idea, and economists are particularly critical. If anyone's interested, the March 2000 issue of the journal Ecological Economics has several papers debating the concept.

Posted by: mgl at April 27, 2004 5:06 PM