Shadow Minister,

While there certainly are countries that would have enough food, were it not for social inequality and mismanagement, Rwanda and Haiti are pretty good evidence that Malthus was right. This is because the population growth in these countries went on to the point where arable land per person was less than the minimum required to produce a nutritionally adequate vegetarian diet for an individual (0.07 hectares according to Vaclav Smil at the University of Manitoba). The Rwandans have dealt with this problem in the time-honoured human way, by killing or driving off some of the competitors for food.

Grain prices have been rising for some time. See this graph from the World Bank

http://econ.worldbank.org/WBSITE/EXTERNAL/EXTDEC/0,,contentMDK:21665883~pagePK:64165401~piPK:64165026~theSitePK:469372,00.html

This graph shows trends in the price of phosphate rock (essential for fertiliser) from 2000

http://www.mongabay.com/images/commodities/charts/phosphate_rock.html

If the famous Ehrlich-Simon bet on the price of 5 commodities had closed in 2008, Simon would have only been right about one of them and would have lost.

http://biolaw.blogspot.com/2008/03/ehrlich-simon-bet-update.html

Ehrlich and others like him were wrong about famines in the 1970s because they could not predict the success of the Green Revolution. You are betting that because technology saved us once, it therefore always will.

Divergence,

If there is no change in technology, such as in Rwanda, and centuries old subsistence farming is used, then Maltheus will be right. With the proper technology the amount of food could easily be tripled.

Another case in point is the "land redistribution" in Zimbabwe, where the "rich" farmers on 35% of the land were producing 70% of the food. These farms were confiscated and given to landless indigenous farmers who were unable to maintain the infrastructure.

The production on these farms dropped between 80% to 90% within a year, and the bread basket of Africa began to starve.

likewise India with a population of 400m in 1960 could not feed itself, but with 1.1bn today can export food.

I think if the famous Ehrlich-Simon bet on the price of 5 commodities had closed in 2009 we might have been back to square one.

The supply of commodities requires considerable capital expenditure, and will take years to catch up with sudden demand changes. The price spike of phosphoric rock by 400% or so in about a year is an anomaly.

If you were to ask how the real prices of commodities compared to the 60s, you will find a huge drop.

This is mostly true for food, as the prices dropped steadily over the decades, but with climate change, there is now a huge focus on biofuel, the supply of food has yet to catch up, and the alternatives to grain and sugar are still being developed.

Technology can't do everything, but even what we have now if applied properly can cater for the 9bn of 2050, assuming that is the peak, and much more.

You are probably correct about Zimbabwe, but Rwanda was down to 0.03 hectares of arable land per person just before the genocide, according to the Worldwatch Institute. Smil does assume modern farming methods, but no expensive chemical inputs. An FAO report gave the figure of 0.053 hectares as the minimum necessary to adequately feed an individual with the full panoply of modern agriculture. Rwandans were basically hungry because there was not enough to go around, and there was a population doubling time of less than 25 years. The marginal and hillside land that had been cultivated was losing its ability to yield. This graph shows grain production from 1960 to the genocide in 1994

http://maps.grida.no/go/graphic/grain_production_in_rwanda

India can now feed itself because the Green Revolution doubled or tripled yields, causing grain production per person to peak in 1984. It may be in trouble, though, when the ground water it is using to grow the crops runs out. See

http://www.sciencemag.org/cgi/content/full/325/5942/79

Divergence,

Just read the link on Rwanda. It would appear that the production is presently lower than in 1960, and even in the 80s it was not much higher in spite of the population quadrupling.

The green revolution saw productivities increase by about 100% in most other countries.

This proves my point.

Shadow Minister,

It is true that there have been problems in applying the Green Revolution in Africa, but even 100% more food than in the 1960s would not have been enough. As you have said, the population has quadrupled, and the Rwandans were hardly living in affluence in 1960. At the time of the genocide, there wasn't enough arable land per person, even with perfect equality and the best possible management. Nor, unlike Japan and some European countries, were they able to trade enough goods and services to the rest of the world to buy the food they needed on the world market. Why is it so hard to admit that people can sometimes outbreed their resource base?