Prophecies Nobody Wants to Hear, part I of V

[Cain]

We're not sure what the earth's real carrying capacity is, and it may be that it's not a hard limit; we can increase it through technology.

The "best guesses" I've seen show a sustainable¹ carrying capacity of about 2 billion with present technology.


¹  Not using this in the hippie/marketing sense.

Joel Cohen, a professor specializing in population issues at Columbia University estimates roughly 5 billion based on the need for 3500 calories a day and the amount of fresh water such a population would need versus the amount actually available.

Naturally, of course, such estimates are open to interpretation, and new sources of food or water (desalinization, if they can ever get it to work properly, for example) can massively impact on that number.

[The Good Reverend Roger]

We're not sure what the earth's real carrying capacity is, and it may be that it's not a hard limit; we can increase it through technology.

The "best guesses" I've seen show a sustainable¹ carrying capacity of about 2 billion with present technology.


¹  Not using this in the hippie/marketing sense.

Joel Cohen, a professor specializing in population issues at Columbia University estimates roughly 5 billion based on the need for 3500 calories a day and the amount of fresh water such a population would need versus the amount actually available.

Naturally, of course, such estimates are open to interpretation, and new sources of food or water (desalinization, if they can ever get it to work properly, for example) can massively impact on that number.

Okay, for the sake of argument, let's accept that figure.

We're 2 Bn over it and climbing.  Add in the innovations Cram has described (vertical farming, etc), and you simply make the problem worse (as Cohen points out, water is an issue.  So is cooking fuel, heating, etc) by allowing an even higher population for a period of time...And by Cohen's estimate - the most optimistic I've seen - we're already living on borrowed time.

[BadBeast]

Food is too much of a necessity for  political stability for it not to be utilized as a weapon by those who have a vested interest
in destabilizing economies for exploitation. Africa is plenty rich enough in natural resources to sustain it's people, it's largely because of the West's policy of making famine stricken countries dependent on Aid that it's so ravaged by Wars. Refugee Populations are shifting across Africa like locusts, because they never get to stay anywhere long enough to Farm effectively.

[Cramulus]

Carrying capacity is a really debatable point. There is a lot of disagreement about where it is. Here's a good chunk from the UN's world population report:

http://www.un.org/esa/population/publications/wpm/wpm2001.pdf

I'm snipping out a lot, but there's a lot of interesting talk about carrying capacity around p44

Carrying capacity and limits to growth

Most efforts at forecasting trends in population growth, agricultural production or economic growth, along with aspects of the environmental impact of the latter trends, extend in range from several years to 25 or sometimes 50 years into the future. Such periods are much shorter than the timescales of concern to ecologists. Yet beyond the near- or medium-term future, most experts in areas such as agriculture or economics believe that unforeseeable future technological and social changes are likely to play such a major role that attempting longer-term predictions becomes a futile exercise.
...

Despite the inherent problems in doing so, many attempts have been made to estimate the number of people that Earth can support. Joel Cohen (1995) compiled and presented all
the numerical estimates he could find of Earth's human carrying capacity. The earliest estimate, by Anton von Leeuwenhoek, dated from 1679; he estimated that Earth
could support 13.4 billion people. Most estimates of carrying capacity are based on an assumption that human populations are constrained by a limiting factor, or sometimes a combination
of potential limiting factors considered jointly. The most commonly assumed limiting factor is the amount of food that can be grown. In addition, Cohen noted that "almost all of the
definitions recognized that ecological concepts of carrying capacity must be extended to allow for the role of technology in enhancing nature's productivity. Most recognized that culturally
and individually variable standards of living, including standards of environmental quality, set limits on population size well before the physical requirements for sheer subsistence" (Cohen, 1995, p. 232).

The estimates of Earth's carrying capacity range from under 1 billion to more than 1,000 billion persons. Not only is there an enormous range of values, but there is no tendency
of the values to converge over time; indeed, the estimates made since 1950 exhibit greater variability than those made earlier (figure IV.1). This is worth noting, as it might be expected that, with the improvement in knowledge of Earth's biological and physical systems, there should be an approach to a consensus regarding Earth's carrying capacity. Yet this is not the case. Cohen concludes that, "notwithstanding their cloak of quantification, many of the published estimates of human carrying capacity are probably less dispassionate analyses than they are political instruments, intended to influence actions one way or another" (Cohen, 1995, p. 233). At the same time, it is worth noting that the world's population has already entered into the zone where many of the carrying capacity estimates are found. Around two thirds of the estimates fall in the range of 4 billion to 16 billion persons, and the median value is about 10 billion, or near the size that will be attained by 2200, according the Population Division's medium-variant scenario (United Nations Population Division, 2000b).

[Cain]

Cram, that is in fact the exact same guy I was citing.

[The Good Reverend Roger]

The rosier estimates are based on unknown technology.

This is akin to the "globalists" saying that off-shoring jobs is okay because manufacturing is obsolete, and someone will come up with another way to generate wealth.  Eventually.

[Cramulus]

Cram, that is in fact the exact same guy I was citing.

yeah I was in mid-post when you posted

[Cramulus]

The rosier estimates are based on unknown technology.

This is akin to the "globalists" saying that off-shoring jobs is okay because manufacturing is obsolete, and someone will come up with another way to generate wealth.  Eventually.

I think it's more unreasonable to assume that we're not going to come up with any solutions in the next 50 years.

[The Good Reverend Roger]

The rosier estimates are based on unknown technology.

This is akin to the "globalists" saying that off-shoring jobs is okay because manufacturing is obsolete, and someone will come up with another way to generate wealth.  Eventually.

I think it's more unreasonable to assume that we're not going to come up with any solutions in the next 50 years.

Convince me it's reasonable to assume we'll develop and impliment that technology in 20 years, and you'll have a convert.

[Cramulus]

Carrying capacity is affected by technology, which is unpredictable. We can agree there, right?

For example, the earth's carrying capacity was increased by the Green Revolution, which measurably increased global crop yields.

[Adios]

Carrying capacity is affected by technology, which is unpredictable. We can agree there, right?

For example, the earth's carrying capacity was increased by the Green Revolution, which measurably increased global crop yields.

So just keep breeding and don't worry about it. Technology will bail us out.

[Cramulus]

*sigh*

[Adios]

*sigh*

*insightful*

[Cramulus]

yeah cause I was totally saying there is no problem and we should just relax 

[Adios]

yeah cause I was totally saying there is no problem and we should just relax 

Sounded like it to me. Just saying.