How much does global warming matter? - concern for environmental problems as opposed to needs of developing countries

Public Interest, Wntr, 1994 by Wilfred Beckerman, Jesse Malkin

MORE THAN A BILLION people in developing countries have no access to safe drinking water, and at least twice that many have no access to adequate sanitation. Consequently, between 1 and 1.5 billion people suffer from water-related diseases such as schistosomiasis, hookworm, and diarrhea. Infant mortality attributable to diarrhea is estimated to be about 5 million per year. But the environmental problems that dominate the media, that are given the most attention by environmentalist pressure groups, and that capture the imagination of the public, are the melodramatic issues. The myth of "scarce resources" is one, and was exposed in these pages by Stephen Moore (Winter, 1992). Another is global warming--"the highest-risk environmental problem the world faces today," according to Vice President Al Gore. The public is bombarded by television images showing the earth surrounded by a layer of "greenhouse gases" (GHGs) that allow the sun's energy to penetrate, but block much of the outgoing radiation from the earth's surface. These images are accompanied by dire predictions that we shall all frizzle up and that the world will become a desert--despite concurrent predictions that rainfall will increase and sea levels will rise. Such scenarios of global warming are much more exciting for the viewer than pictures showing that what the world's population needs most are more lavatories and better sewage systems.

I.

The "consensus" opinion on climate change, as embodied in the 1990 report of the International Panel on Climate Change (IPCC), is that a doubling of equivalent carbon dioxide (an index that summarizes the effect of all man-made GHGs), is likely to occur within the next fifty years if nothing is done to reduce C|O.sub.2~ emissions. Because of the time lags in the dynamics of climate change--notably those caused by the inertia introduced into the system as a result of the absorption of carbon dioxide by the oceans--the temperature increase associated with this warming commitment would not be realized until approximately 2100. At that point, the global mean surface temperature is predicted to increase by between 2 |degrees~ and 5 |degrees~ Celsius. This conclusion has not gone unquestioned. To be sure, the scientific work that has gone into climate modeling represents a major intellectual achievement. Yet it is widely recognized that these estimates have a wide margin of error and that there are still great gaps in our understanding of how the climate is determined. The IPCC report itself contains hundreds of pages of misgivings about the potential temperature increase, and many climatologists have expressed skepticism about the reliability of the global climate models that forecast significant warming.

For example, equivalent C|O.sub.2~ levels have increased by over 40 percent during the past 100 years, yet the climate has not responded in the manner predicted by the models. Consider the following anomalies:

* The amount of global warming that has occurred over the past century--roughly .45 |degrees~ C--is at least a factor of two less than that predicted by the most sophisticated models.

* The Northern Hemisphere, which the models say should have warmed more rapidly than the Southern Hemisphere, is no warmer than it was a half century ago.

* The models say warming should occur as a result of GHG buildup, but most of the warming during the past 100 years occurred prior to World War II--before most of the GHGs were emitted.

Clearly a dose of skepticism is warranted. But let us suppose that the skeptics are wrong--suppose the earth's temperature does rise by somewhere between 2 |degrees~ C and 5 |degrees~ C. How damaging is this likely to be?

II.

There is one simple piece of evidence, which does not require vast computerized models of the world's climate or economy (our understanding of both being extremely limited), and which does at least refute the widespread notion that the human race is some tender plant that can only survive in a narrow band of plus or minus 3 |degrees~ C. This is the present dispersion of the world's population throughout widely different temperature zones. For example, taking the average temperatures in the coldest month in the countries concerned, 32.3 percent of the world's population lives in a band of 0 |degrees~ C to 3 |degrees~ C, whereas 18.8 percent live in a band of 12 |degrees~ C to 15 |degrees~ C, and 14.6 percent live in a band of 24 |degrees~ C to 27 |degrees~ C. Furthermore, across the world as a whole there appears to be no correlation at all between average temperatures and income levels (even excluding the Middle Eastern oil states).

Of course, it will be argued that such cross-country comparisons do not adequately take into account the difficulty of adjusting to relatively rapid changes in temperature. There is some truth in this. But as the distinguished economist Thomas Schelling has observed, the sort of rapid climate changes experienced throughout history by vast migratory movements of population were far greater than those predicted to occur during the next century as a result of global warming. The human race has always been a highly adaptable species, and is likely to become increasingly so, since most of its adaptability comes from its accumulation of technical knowledge.