Sunday, January 17, 2010

10. The Effects of Global Warming

Popular discussions of the consequences of anthropogenic global warming (AGW) and the need for drastic action usually amount to cries of alarm about alleged threats, unsupported by any serious analysis. For example, the Friends of the Earth claim that "an average global temperature rise of more than 2 degrees compared to pre-industrial times would cause dangerous and even catastrophic impacts. Exceeding 2 degrees will create water scarcity for billions of people, put billions at risk of hunger, make hundreds of millions homeless because of flooding and threaten the very existence of low-lying island nation states through sea-level rise."

It is quite easy to show that these concerns are wildly exaggerated and that the proposed remedies are much worse than the alleged problems. First, growth in the human population during this century is very likely to cause regional water shortages, regardless of climate changes. Solving this problem will require desalination of seawater on a large scale. The technology is already available that can provide an unlimited source of potable water at affordable cost, as long as energy remains near present prices. The policy now proposed by the AGW Lobby seeks to curb CO2 by deliberately increasing the price of energy; this "solution" will turn a quite manageable problem of water supply into a major humanitarian catastrophe.

Second, the overall effects of moderate warming on global agriculture, and hence on the food supply, would be beneficial, not harmful. Virtually all studies of global warming indicate that the principal effect would be a reduction in the temperature gradient from the equator to the poles. In other words, most warming would be at higher latitudes, with relatively little change in the tropics. The growing season would therefore be longer in most temperate agricultural areas. Moreover, the southern edge of the permafrost would move north in Alaska, Canada, Scandinavia and Siberia, and the fringe of boreal forest along that boundary would follow, increasing the area of potentially arable land. For every increase of 1oC (1.8oF) in the average temperature in the region, Canada in particular would gain useful land comparable in area to the state of California. In combination with the productivity improvements due to increased CO2, the overall result would be a substantial improvement in the global capacity to feed the growing population. Conversely, global cooling would lead to a reduction in agricultural production.

A warming global climate could entail alteration of regional weather patterns that require modification of the optimal crops grown in different areas, adaptations that might be difficult for some farmers. The necessary changes are however trivial compared to those that will result from extension of modern agriculture to the Third World. Judging by US experience during the 20th century, the development of market economies will largely eliminate subsistence farming; agribusinesses will replace small farmers; irrigation will become common; and the fraction of the workforce engaged in agriculture will shrink by an order of magnitude. The food distribution system will also need changes, but they are well within the capability of commercial enterprises, and do not constitute anything like a crisis.

If widespread hunger persists in a moderately warmer world, the primary cause will be poverty, not climate change. Raising the price of energy in an attempt to fight AGW will increase the cost of living for everybody, exacerbating rather than alleviating the problem.

Third, the "low-lying island nation states" usually identified as threatened by a rising sea-level are Tuvalu in the Pacific (population: 12,373) and the Maldives in the Indian Ocean (population: 396,334).  Without even considering the seriousness of the alleged threat, it is sufficient to note that 5000 people are already leaving these countries each year, in search of better economic opportunities. If this trend continues, the islands will be depopulated before the end of the century, regardless of AGW.

To put these numbers in perspective, 1.1 million legal immigrants are naturalized in the United States each year, and world population growth means that places must be found for 80 million extra people every year. In comparison, the logistic problems of resettling these island populations are entirely negligible.

Destruction of indigenous cultures in these and other remote areas is an issue that needs more attention, but climate change is a minor threat compared with the influence of the emerging global civilization. Can traditional cultures survive when the people begin to enjoy the very real benefits of modern medicine, education, computers, household equipment, etc? Even if village elders prefer the old ways, is it fair or reasonable to force young people to accept them? If teenagers are seduced by iPods and blue jeans and video games and MacDonalds, telling them that they must be satisfied with grass huts and subsistence hunting and fishing will just drive more of them to migrate elsewhere. There are, and there will be, many more cultural and occupational refugees than climate refugees.

The crucial issue of the 21st Century is not how we can deal with relatively minor changes in climate, but how we can solve the worldwide problems of poverty, hunger, illiteracy and disease. If we can create an affluent, high-tech, green and pleasant world, can we or should we preserve pockets of primitivism?

I don't know the answers to these questions, but it seems to me that they must involve finding appropriate compromises between traditional and modern values. The solutions will no doubt be different for different people, such as the Inuit, Pacific islanders, and African bushmen.

1 comment:

Anonymous said...

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