Malthus coming back to haunt us

In 1798 Thomas Robert Malthus published "An Essay on the principles of population". This very influential book is not only the first book on population growth to receive wide public attention, but it is also best remembered for the thesis that population growth will outpace the increase in food production, thereby invariably leading to poverty. You may remember it from high school: Food production growth according to Malthus is likely to increase along a slow arithmetic progression while population growth follows a much faster geometric progression.
Well, Malthus did not take the productivity increases that modern industrialized agriculture brought about into account. Indeed, Malthus' model is overly simplistic, ignoring many other factors that affect the growth of food supply versus population growth: Wars, natural disasters, epidemics, changes in diet, and on the other hand, new productivity increases through better agriculatural methods, fertilizers, irrigation etc.
The bottom line is: For more than 100 years, the world was happy to see that Malthus was wrong.
But was he really? Maybe he wasn't right on how long it would take to get to the point where there are more people on the planet than the earth can feed, but if the population continues to grow, eventually there will not be enough food for everyone. This is obvious and inevitable.
When I was 16 or so, I remember realizing at some point how incredibly many people live on the Earth. Back then more than 4.2 billion people lived on our planet. I found that number shocking and worrying. According to wikipedia (http://en.wikipedia.org/wiki/World_population), the world population is estimated to be about 1.5 times that - an estimated 6.7 billion people today. Furthermore, continued population growth is expected until about 2050 when the world population will peak at about 9 billion.
For decades now we all have lived in a stark imbalance between the rich nations in the north and the poor nations in the south. According to the world health organization, about 1/3 of the world's population is well-fed, 1/3 is under-fed and 1/3 is starving. Today, hunger and illnesses caused by malnutrition are the single greatest cause of death world-wide, accounting for 58% of all mortalities - about 36 million people in 2006 (http://en.wikipedia.org/wiki/Malnutrition).
I saw a documentary on "Arte TV" ("Die Hungerkrise - http://www.arte.tv/de/woche/244,broadcastingNum=963998,day=6,week=50,year=2008.html) about a month ago that discussed the reasons for this situation and outlined what is likely to happen in the future.
Reasons:
- Population growth and industrialization using up more and more farm land
- Pollution and climate change increasing the size of deserts and arid land.
- Pollution and climate change decreasing the world's harvest. According to the Arte documentary, a 1 degree (celsius) increase in the average temperature will lead to a 10% decrease in harvests, mainly in the tropics and subtropics (e.g. Africa).
- Changing world diets: As a general rule, it takes about 6 calories of plant-based food to create 1 calorie of meat. Cows in particular require a lot of water and grain and produce a lot of methane. The more meat is produced and consumed, the less food is available overall. Particularly the growing economies in Asia (India, China) experience a diet change. More and more people are eating poultry, meat and fish.
- The last century saw a dramatic increase in food production due to widespread use of fertilizers and other chemicals. It is unlikely that similar increases are possible in the future - quite the opposite, negative effects of over-fertilization and the use of other chemicals are likely to lower productivity.
- Overall decrease of fresh water. See also the "virtual water" concept developed by professor John Anthony Allen (http://en.wikipedia.org/wiki/Virtual_water).
- Increased production of bio-fuels further reducing the available food supply.

The "arte" documentary went on to explain what the consequences will be:
- More and more countries will be unable to feed their population. They will need to procure agricultural products on the world market. As food becomes more and more scarce, the market prices will rise. The poorest will be the first to be unable to obtain enough food to survive.
- The scarcity of food will lead to "hoarding" making even less food available on the world market, thereby increasing prices.
- The increased prices will lead to speculation on the mercantile exchanges, driving prices up even further.
- Food riots will increase, destabilizing entire nations. The most widely notices food riots in 2007 were in Egypt, Bangladesh, Haiti and Mexico (http://www.cnn.com/2008/WORLD/americas/04/14/world.food.crisis/)
- Conflicts over water rights will increase, leading to potentially armed conflicts
- Populations in famine-stricken regions will try to flee, increasing the number of refugees. Refugees are generally not able to take care of themselves thereby putting a strain on the host nation's resources. Eventually, borders will be closed.

Two factors contribute to the world's inadequate reaction to this increasingly severe problem:
1. People are generally unable to think in exponential growth rates:
You may remember the famous example of the water lilies. Let's assume there is a lake in which the number of water lilies doubles every day. After 30 days, half the lake is covered in water lilies. The question is: How long will it take until the entire lake is covered. Very few people realize that the lake will be completely covered by the next day.
2. People generally do not focus on "critical factors". Critical factors are those that compound the gravity of a situation, thereby leading to more dramatic results than expected. It gets especially dangerous when several critical factors compound each other. In this case there are several critical factors that will cause the situation to worsen much more quickly than most people expect:
- Climate change -> decrease in arable land and decrease in harvests
- Diet change -> Less food available overall because an increasing amount of food is used up for meat production
- Decrease in available fresh water: China has all but used up its (self-replenishing) gound water in many regions. It is now drilling deep wells to access deep water aquifiers. These are not self-replenishing. When they run out, China is (to a large degree) out of water.

For a good discussion of how humans fail to deal with complex situations, I recommend: The Logic of Failure: Why Things Go Wrong and What We Can Do To Make Them Right
by Dietrich Dorner
Metropolitan Books, Henry Holt and Co., New York, 1996, translated by Rita and Robert Kimber, ISBN: 0805041605, $25.00. Paperback edition: The Logic of Failure: Recognizing and Avoiding Error in Complex Situations, Perseus Press, Cambridge, MA, 1997, 222 pages, ISBN: 0201479486, $16.00.

The big questions are: What can be done about this? What can I do to help? What does this mean for my life and the lives of the people around me?
I'll discuss that in one of my next blog entries. Stay tuned...