only big populations can tackle big problems

The overwhelming majority of the big problems we face are caused in the first place, or severely exacerbated, by having a big population.

Resource depletion - too many people
Disease - too many people
Famine - too many people
Drought - too many people
War - too many people
Poverty - too many people
AGW - too many people

"Mortality", in and of itself, is about the only big problem we face that isn't caused by overpopulation.

Mike, one of the generally accepted reasons for the advent of the renaissance: the plagues reduced the European population suffiently that there was a sudden surplus of resources for the survivors.

Birth rates are already dangerously low as it is, the last thing we want is governments encouraging the situation. Italy has the right idea - pay mothers to have babies. Go babies!

Here we go with another ill-informed neo-Julian/cornucopian "birth dearth" myth promoter. This at a time when we've passed yet another population milestone (6.5 billion and rising), and there are few ecosystems on earth that have not been degraded by the ever-expanding human footprint.

Despite there being a few high-population density countries, like Italy, facing a declining birthrate (which should be cause for celebration, not panic), the vast majority of the world --especially the poorest, least stable regions-- is still full steam ahead, adding 75 million a year. Far from facing a "Children of Men" dystopian scenario, we are probably a lot closer to a "Soylent Green", or perhaps Star Trek's mythical planet "Gideon".

If we are ever lucky enough to have world leadership enlightened and courageous enough to tackle population growth, this would be a cause for celebration not worry, as the neo-Julians would have us believe. Imagine a world of "only" 1 or 2 billion (already larger than the human population for all but the last 200 years of our existence).

Imagine every human being being able to enjoy an American or European standard of living, with first-world food, clothing, shelter, education and health care, while simultaneously reducing our ecological footprint. Now contrast this with a population roughly double the current size, which will happen within 50 years, assuming our current growth rate just holds steady. Imagine 13 billion people --most born in the third-world-- in a post-peak oil world of vastly degraded ecosystems and fierce competition for dwindling resources.

Which future would you prefer?

The earth is about 4 billion beyond it's carrying capacity . This strictly a result of oil. It's a mathematical impossibility that these peopole can be fed. DO a little research and look at what percentage of imported food places like ALgeria and Morocco rely on. These places will be seeing massive famines before 2020. What would it be like to watch your child starve to death? This is going to happen millions and millions of times over. The end result of overpopulation is cruelty and suffering on a massive scale.YOu will easily live to see this. Soon.

It's strange, Mike Hearn, that you call us doomers when it's people with your mindset who would doom us all.

One thing that really struck me was that "There's not even any real reason to believe fewer people would decrease consumption (as opposed to simply making the ones who are left richer)." Well, so you obviously admit that all else being the same, fewer people would be richer. In any case, with our current population, it's impossible for us all to be rich. Imagine that China, India, Africa, and the rest of the world got as rich as Americans. Any optimist, even, who is semi-rational (probably including you) would realize that that is an untenable situation. Yes, I mean that all of our 6.5 billion people can't live like Americans EVER, simply because of a lack of resources - oil just being one. If 6.5 billion is an impossible proposition, then 9 billion by 2050 is even more outrageous. I'm not a doomer. I'm someone who wants to make sure that doom is minimized as much as possible. (If a guy has a gun up to your head, will you worry but think of ideas about how to get out of the situation you're in (=be a doomer) or just smile and wish more people had guns pointed at you, and know that everything will turn out OK (=be an eternal optimist with no plan of action)?

I'm fully aware that China's fertility is currently under natural replacement values. I'm sure that most of us have heard of the "one child policy" there, which is actually not so simple as the common English name makes us believe, but it is true that Chinese are having fewer than 2 children per couple. On the other hand, the population of China is STILL GROWING. In fact, China is adding more people every year than many other countries, just because it's population is already so large.

I'm also of the opinion that immigration delays the inevitable, but I differ from you on some major points. The inevitable fact that immigration delays is that our population can never grow forever. It can never reach "infinity", and the amount of resources on this planet (or the solar system, or the galaxy, or the universe) are not infinite - thus finite. Populations have grown rapidly over the world. Just one example is the Philippines, with a population that went from around 7 million to 80 million in just the past 100 years. Imagine how much richer each person in that country would have been if the had only gotten up to 25 million by now. Just in terms of resources, with over 10 times the population of 100 years ago, each person has less than 1/10th the amount of resources available to him/her. And if they decided to be environmentally friendly with a stable 7 million population and only use 5 times as many Philippine resources as the people of today, fully 1/2 of the country could stay pristine. (Of course, I understand importation of goods, but importing finite materials only takes away from others in the world.)

I'm sure that people 100 years ago, who still believed in more growth, would, when asked what a good stable population for the world should be, would venture guesses like 3 billion or 4 billion. Now, at 6.5 billion, many would state figures like 9 or 10 billion. If we reached 12 billion, we'd probably venture guesses like 15-20 billon. Thus, we never realize even when we cross that line into overshoot territory because we're just so used to the population we have now that we always think that a little more is possible. And then when we've added that "little more", we get used to it and believe that a little more still is possible. I'd venture to guess that we're now far over the human population limit that the world can support. And if we're not, who cares because we wouldn't need to reach that limit. Even staying at that limit means that people will only barely get by. Why not have, as you state so unexpectedly brilliantly, FEWER PEOPLE BEING RICHER.

In the end, each country (and the world in general) will have fewer and fewer resources to work with as time goes on. There will be less oil each year after peak oil. Even if it weren't now, and oil production increased in some way for the next 300 years, imagine how much more damage a constantly growing world would have done by then.

Keep this in mind. The amount of oil we'll be able to use will be falling year after year in the future, so the populations of nations had better be doing the same thing by family planning methods, or else it will be starvation that will do the job for us. Maybe I'm a doomer. But I'm a doomer with ideas.

a) I'm not aware of any projections that suggest we're going to add 15 billion people to the planet in the next 100 years. The most recent UN projections put the population at around 9 or so billion by 2050, with the likelihood of it plateauing and even decreasing after that point.

b) Can you actually numerically prove that there are "not enough resources" to sustain 8 or 9 billion people living in 1st world conditions? Sure, we'd have to recycle a lot more, and food production techniques would have to be overhauled fairly dramatically, but there seems little justification for being convinced that it's impossible. For mainly political reasons, I suspect it will be at least another 100 years before even 50% of the the world's population IS living in 1st world conditions, and by then total population will most likely have dropped back to something close to what we have today - possibly somewhat less, but to get there won't require levels of mortality massively greater than what we already have today. Of course, it's entirely conceivable that if we get it wrong, there will be massive mortality rates in any number of parts of the world over the next 50 to 100 years, but believing that it's impossible to do anything about it is dangerous and unjustified.