Clownfish, you appear to be advocating a "crisis management" approach - to only address a problem when it becomes essential to do so. However, planning for success has been the more favoured and effective way to ensure achievement of stable outcomes. Failing to plan has been described as "planning to fail". I tend to agree. It is only prudent to consider all supply and demand pressures in the development of strategies to avert crises and structural collapse.

The overriding question is whether "business as usual" is the best possible way forward, or should we rather be planning to resolve issues of inequality, repression and conflict which are rife in many quarters, before the human condition kicks into override and results in all-out aggression in pursuit of dwindling resources.

I would advocate planning for peace, equity and stability as being far superior objectives to strident maintenance of current unsustainable divisiveness.

popnperish, I'm sure the empty-headed numpties in Harold Camping's church are quite happy to follow him, too.

It's a sadly demonstrated fact that, no matter how incontrovertibly wrong the predictions of doomsayers prove to be, their acolytes will loudly and loyally insist that they were, in fact, right. Ehrlich's fans are, unfortunately, no different.

There is absolutely no reason why we should be entering an 'energy constrained future' (apart from the screeching ninnies in the Climate Alarmist movement). Known reserves and current technologies alone guarantee plenty of energy for centuries yet - without reckoning on new technologies.

Who, little more than a century ago, could have foreseen the end of the great horse-poo crisis then literally engulfing the world's cities?

You're making the same mistake (or committing the same sophistic sleight-of-hand) as Jared Diamon by singling our Somalia and Yemen. Two isolated areas, one of which at least owes its problems more to poor political governance than anything else.

Saltpetre, I merely point out that Divergence and popnperish, as with all neo-Malthusians, from Malthus himself to Paul Ehrlich, fatally underestimate human ingenuity.

The solutions, as unexpected, unpredicted and surprising as they will be, will be there.

Clownfish
There's a difference between the adherents of Harold Camping's church and my support for Ehrlich. The difference is a choice between religion (and a quasi religion at that) and science. Every step of the way I look for evidence to back up what I support, and the evidence is in that we are in overshoot, that we have exceeded the Earth's biocapacity by 40 per cent and that another 2.4 billion by mid-century is going to make it very hard to feed everyone (which is what Julian's essay is all about).
Let's hope you're right on the energy front but there certainly WILL be a liquid fuel crisis in the next few short years because we don't have in place alternatives to oil.It's not running out (a trillion barrels to go) but it will become increasingly expensive which will be very disruptive to our economy and life as we know it.

Clownfish,

I had an exchange with you here on OLO back in 2008, when grain prices skyrocketed and there were food riots in 34 countries. You claimed that this was a purely temporary phenomenon, a "perfect storm" of unusual events all coinciding. I agreed that some of the issues, such as the drought in Australia, were indeed temporary, but thought that others were continuing problems. The UN FAO food price index is even higher now than it was then, higher than it has ever been, in both real and nominal terms, and high food prices have been a factor in the revolts in the Arab world. See

http://www.fao.org/worldfoodsituation/wfs-home/foodpricesindex/en/

It seems that your record as a prophet isn't much better than Paul Ehrlich's. I could say, "What a hoot!"

People have, of course, been recycling phosphates since the invention of agriculture, but a lot still ends up in the oceans. The question is whether there will be enough to sustain today's very high agricultural productivity. There are other factors too. See Julian Cribb's video

http://vimeo.com/23244839

I gave you a list of unsolved problems that people in the 1940s and 50s were assured would have been solved by now by the popular science writers of the day. How is this possible with human ingenuity at work? Wouldn't it be smarter to be prudent for the time being?

popnperish, and Divergence,

If the principal components of food (and organic matter generally) which are converted in digestion, or in energy production, are the sugars, starches and cellulose (and maybe some nitrogenous compounds), leaving the trace elements largely intact, then, by inference, total recycling of "waste" could theoretically enable retention of the majority of the components necessary to "reconstitute" food by the application of photosynthesis in the presence of sunlight, CO2 and water - and possibly with the addition only of some nitrogenous fertilisers.

If so, perhaps the answer to food supply is effective recycling of all organic and non-organic waste, together with intensive management of the water supply.

To some (more limited) extent, it may also be possible to recycle oil-based waste, to eventually reduce the extent of reliance on "reserves".

As with all "alternatives" to conventional exploitation, cost will be a factor, and "viability" will be determined in due course by market forces.

I still think solar energy is far under-rated as a potential solution for food, energy, and oil for chemical and plastics manufacture, etc. The sun is an immense, and virtually limitless, energy source, which could be employed with appropriate bacteria and algae (or other organisms - if necessary, genetically modified) to manufacture just about anything. We just need a far more efficient and cost-effective way to harness the sun's energy. (As well as far more efficient ways to recycle our waste.) Waste not want not?

Saltpetre
Unfortunately, we cannot recycle energy thanks to the second law of thermodynamics that basically says the universe is constantly losing usable energy and never gaining. So using oil turns it into either work or unusable heat.
As for elements such as phosphorus. Plants take it up and it is consumed by humans who excrete it. Unless returned as 'night soil' (common in parts of the world still today) then, as Divergence says, it generally ends up in sewerage and ultimately the sea.
But yes, we do need to recycle more and try and retain more of valuable nutrients so we end up with a closed, not an open, system.