[seclorum]

> Past performance doesn't guarantee future returns.

You might want to consult the factual record of tens of thousands of years of farmers on that particular point of view. ;) You are right that it doesn't guarantee anything, except to those who carefully apply scientific principles to their management of resources, folks otherwise known as 'farmers'.

>he standard of living should also be considered. Given that we can support 9 billion people, will each of them be as well off compared to if we were instead supporting half that?

For at least the last 200 years, the standard of living of hundreds of millions of people has been raised, again and again, over and over. So I'd say, if we can manage it, this trend will continue. I think thats the point of the article: there are no environmental reasons, at all, why we couldn't manage to sustain life on Earth, indefinitely.

(There are only psychological reasons. A fact proven, nearly, by a lot of the responses in this thread ..)

[fiter]

> You are right that it doesn't guarantee anything, except to those who carefully apply scientific principles to their management of resources, folks otherwise known as 'farmers'.

Wouldn't science suggest we model based on the systems as they are instead of past performance? Let me hypothesize for a moment here to create a situation where the past performance may fail for predicting the future: (1) Assume that plants have traditionally been nutrient limited. (2) We are no longer nutrient limited. (3) We are now insolation to stored energy limited. We don't have a good way to increase insolation, so we'd better come up with a way to increase the efficiency of photosynthesis. (Not to say that there aren't plenty of ways around this. Maybe we'll use solar cells to power chemical sugar making plants.)

> For at least the last 200 years, the standard of living of hundreds of millions of people has been raised, again and again, over and over.

You quoted me, but I'm having a hard time interpreting your response in the context of you understanding me. I was stating that we might be better off with less population, not simply that the standard of living can increase with an increasing population. To state it again, we could have X% increase with double the population, but with our current population we might have Y%. Is Y > X?

[lutusp]

> there are no environmental reasons, at all, why we couldn't manage to sustain life on Earth, indefinitely.

The linked article doesn't say we can sustain our numbers indefinitely, It argues that we can grow our numbers indefinitely. Grow != sustain.