Saturday, December 10, 2011

Chinese food energy production and consumption: an export land model analysis

Past series (starting here and here) have defined units and the terms used here, and, explained how I derive food energy contents for the various food items reported by the FAO, and how these aggregated data can be used to estimate overall food energy production, consumption and export/import rates for individual countries, regions, or the entire world. 

This analysis shows that China has long been a net food energy importer, although the trend as accelerated in the past decade.  Throughout, where pertinent, I will point out differences compared the USA’s food energy situation, the details of which have been presented previously starting here. 

Net Food Energy Production for China

Figure 1 shows the time course of the changes in total net food energy production (blue), and the two major subcategories of plant-derived and animal-derived net food energy production, and its population:

China’s total annual net production rate (blue circles), has increased from about 2067 PJ/yr in 1961, to about 9754 PJ/yr in 2007.   That’s a 4.7 times increase, which is much greater than the 2.4 times increase in the USA food production over the same period.  In part, this dramatic percentage increase is because China's food production was so low in 1960s. 

For instance, I find it amazing that in 1961, with a population (661k), over three times larger than the population of the USA (189k) at the time, China produced 2067 PJ of food energy, only 63% of the food produced in the USA (3246 PJ/yr in 1961). 

It looks like China’s total net food energy production overtook the USA’s total net production around 1983, and is now substantially higher than the USA’s (7871 PJ/yr in 2007),   But of course, so too is its population, at 1.3 billion in 2007 (versus only 0.3 billion in the USA in 2007); a doubling since 1961.

As illustrated in Figure 1, plant-derived food energy dominated China’s food energy production until about 1985, when animal-derived food production started to increase.  Consequently, animal derived food production has risen 22 times from nearly nothing in 1961 (52 PJ), to 1172 PJ in 2007.  That’s right, a 2,200% increase!  Still in 2007, 88% of food energy production is derived from plants, with the remaining 12% derived from animals.  This proportion of animal-derived food energy is actually higher than in the USA in 2007 (about 10% in 2007). 

I think that these dramatic increases in China’s food production are all signs of the petroleum-driven Green revolution having occurred in China throughout the 70, 80s, and 90s, but, more about that later.

You can see from Figure 1 that the rate of Food production especially from 1961 to 2000 has outstripped the population increase. For instance, the average year-by-year population change from 1961 to 2007 equals 1.5±0.6 percent, while the average yearly change in net food energy production equals 3.3 ± 3.4 percent.

However, since about 2000, there are signs that the rate of food production is slowing down (arrows) compared to the longer trend.

Figure 2 shows this slowing trend more explicitly, presenting the 5-year averages of the year-to-year percent changes in net food energy production (total, animal and plant), and, the population change.     

Similar to the USA, the 5-year average of year-to-year change in total net production are quite variable, ranging from 8.6%/yr in 1962-66, to only 0.52%/yr in 2002-07, with even wider variation in animal-derived food production, no doubt because the starting number in 1961was so small!  In comparison, the 5-year average year-to-year change in population has been steadily declining, e.g. from 2.2%/yr in 1962-66 to only 0.66%/yr in 2002-07. 

Figure 3 presents the same data as in Figure 2, but as a scatter-plot of the 5-year averages of the year-to-year percent changes in population and food energy production as function of the mid-year of each 5-year averaging period.  The solid lines show the linear regression best fits.

Figure 3 shows the strong linear trend (r2=0.89) for the decrease in the growth rate of in population and more scattered (r2=0.41) declining trend in the net food energy production growth rate. 

Are these statistically significant linear relationships?
I used the EXCEL function LINEST to generate the F value for these regressions lines: 58.3 (population) and 5.9 (food production).  The EXCEL function FDIST (n=9, df=7, so v1=1 and v2=7) was used to estimate the probability of a higher F value occurring by chance alone: 0.000123 (population) and 0.045 (food production).  So yes both of these are statistically significant relationships; although the higher scatter in food production growth means that my assurance of its predictive capability is less than future predictions of declining population growth.

Extrapolating these linear regression lines suggests a cross-over in about 2013-14 (i.e., the food production growth rate less than the population growth rate) and both of these reaching zero growth at or before 2020 (specifically zero food production growth by 2016 and zero population growth by 2020). 

Of course, food production growth dropping faster than population growth is not a good sign—it means that the difference would have to be made up with imports. 

Contributors to Net Food Energy Production
Figures 4-7 presents major food items that contribute to the plant-derived and animal-derived net food energy production rates.
Figure 4 illustrates that, as noted above, as a percentage of the total food energy production, total plant-derived food energy dominated food production (e.g., 97% of total production in 1961, staying above 95% until 1986), and is still very important at 88% in 2007. 

Similar to the USA, of the seven subcategories of plant-derived food energy depicted in Figure 4, cereals are the major food type produced in the China, ranging from 68% of total production in 1976-79 to 53% in 2007.   All of the other food types make relatively minor contributions (less than 10%) to net food production.

Figure 5 focuses on relative contributions of the "big four" plant food items that were important in my previous post (starting here) analyzing the world-wide production trends: maize (corn), wheat and rice, and, soyabean plus oil from soyabean. 

The sum of these four food items has provided anywhere from 52% to 64% of total net food energy production in China from 1961 to 2007.  The most recent 2007 value 56% is in about the middle of this range.  This is somewhat less than the contribution from these four food in the USA (about 75% in 2007).

Not surprisingly, rice is THE major food energy item produced in China.  But, after peaking in 1972, at 34% of total food energy production, the proportion of rice’s contribution has been steadily declining and in 2007, was at its lowest proportion ever, at 19.7%.  Surprisingly, to me at least, is that corn (maize) has made up for a good amount of rice’s decline.  Corn is everywhere, even in China, it seems. The proportion of corn’s contribution has increased from 11% in 1961 to equal the same as rice, 19.7% in 2007.  So, in China, corn is now just as important as rice, at least in terms of food energy.   The proportion of food energy coming from wheat has also increased, up from 8% in 1961 to 13% in 2007; it looks like wheat’s relative contribution peaked in 1985 at 17%.

Corn’s rise to prominence in China is still far below that of the USA—in the 2007 corn accounted for 45% of total food energy production in the USA, while rice was less than 1%.

Figure 6 shows the relative contributions from all nine different cereal items separately identified by the FAO: Wheat, Rice, Barley, Maize, Rye, Oats Millet, Sorghum and “Other”

This plot show the historical dominance of Rice as the most important cereal crop and the subsequent rise in corn and wheat.   I wish I new what “other” corresponds to in China, as something other than the 8 specific cereal has played an important role, and, then has dropped off a cliff since about 2003—but I have no idea what that sereal item could be.  Any ideas, anyone?

All of the other cereals, Barley, Maize, Rye, Oats Millet, Sorghum, have also dropped in significance since the 60s and 70s.  Rice, corn, wheat, and "other," is where it is at in China.

Figure 7 shows the stupendous rise in animal-derived food energy from a mere 3% of total food energy production in 1961 to 12% in 2007. 

This trend is almost the complete inverse to that of the USA, whose animal-derived food energy has declined from about 14% in the early 60s to about 10% since then.  Meat-derived food energy accounts for the bulk of the animal-derived food energy increase in China, although all the other categories depicted in the figure have also increased.

Consumption of Food Energy
Figure 8 shows the distribution of the Domestic Supply of food energy in China:

Clearly, the human food energy supply has been, and remains the major use of domestic food energy, although its proportion has been steadily declining from 68% in 1961, to 54% in 2007.  Food energy for feed, processed food and other uses of food (all except seed) have increased, but still even in aggregate, they account for only about 45% of domestic food energy use.

These proportions of domestic consumption differ significantly from the USA’s, where Feed is the dominant domestic food energy use.  For instance, in 2007 food consumption for feed was at 34% of the total domestic food energy supply in the USA, and the human food energy supply accounted for only 30% of domestic food energy consumption.

Net Production, Consumption and Net Imports
Figure 9 shows China’s annual food energy net production and consumption (domestic supply) and the difference—growing net imports (i.e., shown as negative exports) since the mid 1970s:
Whereas the USA is a net food exporter, China is a net food importer.  For instance whereas the USA, net exports equaled 1616 PJ of food energy in 2007, China net imported 903 PJ of food energy.

The trend has been for food imports to be increasing, although as a percentage of total domestic consumption imports are still small.  For instance, in 2007, net food imports (903 PJ) only accounted for 8.5% of total domestic food energy consumption (10659 PJ).  Still, the separation between what domestic food production provided versus domestic food consumption has increased since 2002, and, appears to be growing.

This trend is shown more clearly in Figure 10, which presents the China’s food imports as a percentage of total food energy production.  To be consistent with previous posts in this series, I present this as a negative number to make clear that these are net imports and not net exports.  The year-to-year variation is quite large, but still, the recent trend for growing food imports is apparent.

It is interesting that food imports are growing even though the rate of population growth has been declining (e.g., see Figures 2 and 3 above).  Perhaps the growing importation of food reflects China’s growing wealth and the ability to pay for food imports.  Or, the growth in food imports reflects a topping out in China’s ability to further increase its food production.  It is probably bit of both, I suspect.

As discussed in the context of Figure 3 above, China’s rate of decline in food production growth appears to be falling faster than the rate of decline population growth, so increasing food imports to make up the difference would make sense, as illustrated in Figure 11:

Figure 11 show the absolute total food energy exports (red) and imports (blue), and net difference between these two (green), which corresponds to the same net export values shown in Figures 9 or 10.
Figure 11 illustrates that food exports have increased about 1.8 times from the mid 80s, (i.e., from 168 PJ in 1985 to 302 PJ in 2007).  But food imports have increased by more than doubled that amount over the same period: a nearly 5 times increase (i.e., a nearly 5 times from 246 PJ in 1985 to 1205 PJ in 2007). 

This is quite different than the import/export picture in the USA, which has had net exports over the last 50 years (albeit flat for the last 30 years). 

Details of net Food Imports into China
Figure 12 shows the net food energy imports derived from plants in total (blue circles), and for several different major categories of plant food items: 
In 2007, of the 902 PJ in total net imports, 862 PJ, or 95% were from plants.  As shown in Figure 12, after being slightly positive in 2003, and negative the year after, the sum of cereal export/imports have been neutral since then.  For the past several years, plant-derived imports have been increasing, mainly from the oil crops and the vegetable oil crops. 

Figure 13 show the food enery imports for the "big four" plant food items; as illustrated, recently maize, wheat, rice are essentially export-neutral, but soyabean and soyabean oil (i.e., the major contributors to vegatable oil crops and vegetable oils in Figure 12) have been major net imports.  In the past, however, there have been periods of cereal import spikes—mainly due to the importation of wheat–centered around 1982, 1988 and 1995. 

These years also coincide with some years in the USA which also had downturns in cereal production, suggesting that there may have been world-wide conditions responsible for these downturns in cereal production.  

China's plant import situation is quite different than the USA, which is a strong net cereal and soyabean/soyabean oil exporter, and even rice exporter. 
It is amusing to think that some of the USA’s net rice exports wind up being exported to China. It turns out that this idea is not too far fetched (see Is China gearing up to import U.S. rice?).  Similarly, the USA is ramping up corn exports to China, thereby in part causing corning prices to increase (corn-based ethanol production being the other part cause price increases; see Markets Hub: U.S. Corn to China Export Quadrupled; USDA Sees More Corn To China).  
A good portion of the soyabean imports could be helping to sustain China’s domestic consumption of food energy as feed (Figure 8) as it deals with severe droughts in the north and as rising incomes allow people to consume more meat (see China's grain demand should boost U.S. exports).

Figure 14 shows the net food energy imports derived from animals in total (blue circles), and for the different subcategories of animal-derived food items. 

The total animal-derived food imports are quite small compared to plant food import, e.g., -41 PJ for animal-derived food energy in 2007, compared to -862 PJ for plants.  Imports of seafood and animal fats have been increased the most over the last 20 years.

China’s Production, Consumption and Imports on a Global Scale
Figure 15 shows China’s food energy net production, consumption, and net exports, as well as population, all as a percentage of their respective global counterpart amounts (which I derived in a previous series of posts here).  

The black line and x’s show that for the last half-century at least, China’s population corresponded to about 20 to 23 % of the world’s population.  Since peaking at 23% in 1975, this proportion has declined to 20% in 2007.  The percentage decline probably reflects both the declining rate of population growth in China (Figure 2 and3) and relatively higher population growth rates in other parts of the world. 

Despite having a declining percentage of the world's population, China’s food energy production and food consumption have dramatically increased as a percentage of the world’s food energy production or consumption.  For instance, in 1961, China with 21.6% of the world population, produced and consumed only about 11% of the world’s food energy.  But in 2007, with 20.3% of the world’s population, China produced and consumed 17% and 19% of the world’s food energy, respectiuvely.

The difference in production and consumption has been made up by tapping into the global food export market.  In 2007, China’s food imports accounted for 8% of the total amount of food energy exported world-wide.

Components of China’s domestic food energy consumption compared to global counterparts
Figure 16 shows the major categories of the China’s food energy consumption, expressed as a percentage of its global counterparts. 
For reference, total domestic consumption (solid red circles and line “% global domestic supply”) is the same as the red line presented in Figure 15.  Also for reference, I show the population as percentage of global population (black xs and line).

As you can see, for the last half century, the proportions of all of these categories have been less than the proportion of China’s relative global population.  That is, even though it has 20-23% of the world’s population, China’s proportion of world food energy consumption for seed, feed, processed food, other uses, and the human food supply, have all been less than 20-23%. 

By the way, this is the complete opposite than for the USA, where all of these components of US food energy consumption are higher in proportion than the USA’s relative to the global population.

China’s relative under-consumption of food is changing however.  The proportion of each one of these categories (except seed) have increased, and in some cases, exceeded 20% of world wide use.

For instance, by 1996, China’s human food energy (pink circles and line; 21.5% of world human food consumption) increased to equal its percentage of the world’s population (21.5%).  Similarly, China’s use of food energy for "other" non-food uses exceeded it's percentage of the global population in 2002 (brown squares and line).  The proportions of food energy consumption of feed and processed food are also on the rise, and will probably also eventually meet or exceed 20% of their respective global amounts, if the trends continue.

Figure 17 focuses in on China’s human food energy consumption of plant and animal food energy relative to the counterpart world human food energy consumption amounts:
Again, for reference, I show  the percentages of the total human food supply (same as the pink line presented in Figure 16), and China’s population (black line and x’s), relative to their global counterpart amounts.  The total human food supply is the sum of plant-derived food for human consumption (blue circles and line) and animal-derived food for human consumption (green circles and line). 

As I mentioned in the context of Figure 16, China’s proportion of the consumption of food energy for human use increased to equal China's proportion of the global population in 1995, and, as better illustrated in Figure 17, since then, has continued to equal or slightly exceed China’s percentage of the global population. 

The percentage of plant-derived human food increased since 1961 to finally equal China’s population percentage in about 1983 (22.2%) and has tracked with China’s population percentage since then. 

Animal-derived food for human consumption had much larger ground to make up.  In 1961, China’s use of animal-derived food for human consumption only amounted to 3.1% of the world-wide amount of animal-derived food for human consumption. 

That’s an incredibly small percentage, considering that in 1961, China had 21.6% of the world’s population. 

It took until 1998 for China’s consumption of animal-derived food to equal 21.7% of the corresponding world-wide amount (21.3%).  Since then, China's proportion of animal-derived food for human consumption has continued to increase beyond it population proportion.  In 2007 China, having 20.3% of the world’s population, consumed 23% of the global animal-derived human food supply. 

Summary and Conclusions

China’s increase in food energy production since 1961 is even more remarkable than the USA’s; a 4.7 times increase (Figure 1) versus the USA 2.4 times increase.  Like the USA, China experienced its petroleum-driven green food revolution.   However, China is showing signs of topping out in its ability to continue expand its food energy production at the same rate as it has in the past  (Figures 2-3) and is now increasingly turning to food imports. 

At the same time, China's petroleum domestic production and foreign imports have dramatically increased (see Figure 1a of Trends in Chinese Petroleum Production, Consumption and Imports).  For instance, since 1965, China’s domestic petroluem production increase from 0.065 bbs/yr to 1.5 bbs/yr in 2010—that’s whopping 2300% increase!  But, the domestic consumption of petroleum has increased even more, and consequently, China became a net importer of petroleum, in 1993. 

The year 1993 also happens to be about the last year that China was close to being net neutral in food energy imports (see e.g., Figure 11) .  Since then, food imports have been increasing.

So, China has become an increasing net food importer, since the early 1990s, despite the fact that its per capita petroleum consumption has more than doubled.  For instance, per capita consumption of petroleum in 1993 was 0.93 b/py (barrel per person per year), and by 2007 it was 2.18 b/py; a 2.3 times increase (see Figure 5of Trends in Chinese Petroleum Production, Consumption and Imports).  Over this same period, however, food energy production increased by only 1.3 times (7433 PJ in 1993 to 9756 PJ in 2007). 

I think that the slow down in food production growth in the face of increasing per capita petroleum consumption, could be an indication that other factor(s) have started to limit China’s ability to increase it domestic food supply.  One or more of water and soil depletion, climate change, urban encroachment of farm land, the migration of people from rural to urban settings and the aging of farmers, could be limiting food production. 

Fortunately, the decline in food production growth is also occuring at the same time the growth rate in China’s population is in decline.  Indeed, sometime around 2020-2021, China’s population will stop growing (Figure 3).  The trouble is that food production growth might reach zero before then (Figure 3).

Additionally, the trend has been for China to consume greater proportions of the world food energy supply.  That is, China is consuming amounts of food energy closer in proportion to its population, and, has also increased its appetite for animal-derived food (Figures 15-17).   These factors have driven China towards being an increasing net importer of food. 

Perhaps, on the bright side, China’s growing need for increasing food imports will provide the USA with a means to improve its trade deficit with China.  On the hand, I don’t see any signs of the USA increasing its net food exports (see e.g,, Figure 9 of the USA study), so China might have to import its food from elsewhere (e.g., Africa and South America).

For the near term, to me it looks like a horse race between China’s ability to keep up domestic food production and importing increasing amounts of food, versus the declining rate of population growth, and with it, hopefully, a decline in domestic food consumption.  For the longer term, the declining petroleum export pool over the next 20 years will start to affect China’s ability to produce food domestically, as per capita petroleum returns to about 1 b/py and food import prices increase and/or exportable quantities of food decrease. 

12-11-11: updated figure 7 and 14 to explicitly state that "meat" includes offals, and, to show fish oil (fish liver oil plus fish body oil) as a separate category.


So, where to next? 

Since we already in the Asia Pacific region, how about India  

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