A new climate modeling study presented this week at the American Geophysical Union (AGU) meeting in New Orleans suggests that much of Africa will experience increasing drought as global warming progresses in the coming decades.
This has been the most difficult, and yet the most important, aspect of global warming to predict: how will climate change on a local and regional basis in the future? People are most affected by how weather will change where they live, not by how much the global average temperature is changing. And, on a whole, humanity is more sensitive to changes in rainfall than to temperature.
About the only thing generally agreed upon about the effect of global warming on precipitation is that it will, on average, increase somewhat (not decrease). The amount of increase is expected to be a couple of percent for every degree F of warming. But regional shifts in the usual distribution of persistently rainy and dry areas are always a possibility, just as those shifts have occurred in decades and centuries past. Natural variability in precipitation is so large that it has been difficult to measure any change in global rainfall due to the 1 degree F warming in the last 100 years.
The new study uses a computerized climate model that suggests that a predicted gradual warming of the Indian Ocean due to increasing atmospheric greenhouse gas concentrations will lead to a commensurate decrease in rainfall over central and southern Africa. The Sahel region to the north (just south of the Sahara Desert), which endured decades of persistent drought until relatively recently, might actually see an increase in rainfall according to the model projections.
It is important to point out that these are model predictions, not observations; African drought does not seem to have yet become more frequent over the last 100 years, despite a modest amount of warming over that period. And model predictions of regional climate shifts have been notoriously unreliable. Finding the "fingerprint" of man-induced global warming-related precipitation changes is so difficult simply because, even without the help of mankind, droughts, floods, and climate changes happen anyway.
Which brings us to the more important question: Why has Africa always been so sensitive to drought, and the resulting famine that often accompanies it? Prosperity doesn't seem to suffer when drought strikes most other countries of the world. Los Angeles is often in a persistent state of drought, and we don't hear of starvation there.
The answer, of course, resides in the government controlled economies of much of Africa. A lack of personal property rights, free markets, and free trade between countries will continue to make Africa sensitive to the whims of Mother Nature, with or without the help of mankind.
This is the tragedy of Africa. We can expect this new climate study to be cited as a reason for reducing greenhouse gas emissions to help "save" the poor of the world. But in reality, what is really needed is political and economic change -- in a word, freedom. Africans need to be allowed to create their own wealth, and trade that wealth (goods, services... including food) with other countries. Creation of wealth requires access to affordable energy, which helps drive vibrant economies. Somehow, the corrupt and economically misguided governments of Africa need to be held accountable for the human suffering they are causing.
Droughts and floods will continue to occur as they always have. Only now, we can expect humans to be increasingly blamed for their existence -- a charge that will be difficult, if not impossible to prove. In the meantime, we should work to make individual countries less susceptible to weather changes, since drought in one location will be inevitably accompanied by increased rainfall in others. We must encourage the spread of freedom, for in this simple word is found not only relief for today's sufferings, but the hope for new energy technologies that will inevitably be devised by the educated and prosperous countries of the world.
