My blog frequently delves into world famine, and one of the critical things about this problem is presenting the information in such a way that everyone can understand it. The Food and Agriculture Organization of the United Nations must spend a lot of money tracking the world food supply, since it is an absolute necessity for life, and one would expect they would be very careful. The food indices shown below are presented routinely, and probably considerable thought and expense went into creating these charts after the data had been collected. The charts look pretty enough but they are not very persuasive because they are unnecessarily difficult to read. For example, try and read this chart for Cereal production, utilization and stocks:
A chart from FAO showing supply and demand of global food cereals looks good but you must read the micro-type instructions at the bottom to have a clue as to what the colorful lines mean. It appears to mean, from the green line, that in the year 2000 the world consumption of cereals was 1900 million tonnes and that in 2010 it was near 2300 million tonnes. The jagged orange line, representing production of cereals generally tracked the much smoother green consumption line, and the whole human food supply system was buffered by the quantity of stocks in the supply lines as shown by the bars. The stocks have fluctuated somewhat but have gone from 600 million tonnes to 490 million tonnes, but this is buffering a larger production and a larger human population so the backup supply is approaching half of what it was ten years ago. The exact same information could have been better presented on essentially the same chart by shifting the graphics slightly to emphasize which data was represented by which index column.
This is an improvement because you don’t have to learn and remember which curves go with which index. It is more apparant that the Production and Utilization on the left refer to the index on the left and the Stocks on the right refer to the index on the right.
A more fundamental problem is that all three of these same quantities being measured (cereals) are on the same zero point, which is invisible, well below the bottom, but the ones on the left are much higher than those on the right. This was probably done because there would be a large gap, but it is a very important gap and so it should be included to make clear the discrepancy between what is being created and consumed and the amount actually available. The graph should look like the one below, which I have created using their data but leaving the graphical presentation on the same scale. It requires showing the very large discrepancy in the production and the storage of grains.
When the information is presented this way with all of the factors on the same scale the relative importance of the stocks becomes more visibly obvious. The movement from production to consumption does not have a very large buffer. It becomes obvious that if production ceased, all of the cereal would be consumed in a few months and then all of the people of the world would starve to death.
People can not understand the connection between food and population control until they understand the relationship between production and consumption, and that depends upon clear presentation of the data.