Historic climate change and national income across three centuries

¶ … Lived Effects of Historic Climate on the Wealth of Nations

bluedorn, john c., VALENTINYI, AKOS and VLASSOPOULOS, MICHAEL

The authors are attempting through their research to make a direct connection between the wealth and prosperity of nations when compared with the effects of long-term climate change, specifically temperature. They propose to conduct their study over three centuries time, the 18th, 19th, and 20th centuries (1730 to 2000) by observing the income data from cross sections of 167 countries. The use historical data sources and base their weighted scale on thirty-year average temperatures specifically oriented to countrywide variances. The major contribution of this particular study is to add to the current hypotheses that climatic temperature has a time-varying, non-monotonic effect upon income as observed in the 20th century and project bock to confirm this theory for the 18th and 19th centuries.

Their data infers that negative temperature changes in long-term weather patterns have a subsequent negative effect on the income distribution on a larger geographic scale. The outcome of this study is a country-level, population-weighted, scale of climatic temperatures over a 270 years time period. The authors admit that their results, while "robust to a host of sub-sample stability and specification checks,"

they are not altogether conclusive to a direct relationship. In fact the data from the 20th century does not parallel the implication of the data directly from the 18th and 19th century. Their conclusion is in fact that, "climatic temperature does not contribute a significant direct disadvantage for current economic outcomes."

The authors admit that while their findings from the data are indeed interesting that more work will need to be done, "A more detailed investigation of the postulated interpretations presented here are left for future research."

Critical Evaluation

While the authors of this article have certain done a well crafted research project, their evaluation of the findings become rather segmented for a global impact study. While they have studied the impact of temperatures on the economic growth of nations over a long period of time, their final conclusions are admittedly vague since the data for more current times contradicts the earlier constructions. They failed to take into complete consideration population growth and the impact that has on the landscape itself as well as the industrial effect of greenhouse gasses upon the population. One glaring omission is the concept of global warming as an important consideration that may affect the data in the more current century. While the authors used one source that particularly address this issue they only pulled the requisite data on colonial settler mortality and not global warming directly. In fact the concept of global warming economics is one that is also not addressed, however the brevity of their paper merely brings up more questions for future research, as the authors themselves indicate at the conclusion.

They did not fully explore, for example, the greenhouse effect which is a natural phenomenon that has been operating for millions of years and without it the Earth would be too cold to support life as we know it. Greenhouse gases such as carbon dioxide, methane, nitrous oxide and chloroflurocarbons (CFCs) in the atmosphere keep the Earth's mean surface temperature at an average of 59 degrees Fahrenheit. "Whilst the greenhouse effect is a naturally occurring phenomenon it is anthropogenic changes to the composition of greenhouse gases that has caused concern in the scientific community, the public and policy makers."

The follwing table may have helped further their research:

Figure 1: Greenhouse Gas Concentrations

This upward trend in greenhouse gases is, theoretically, the result of the waste material of modern civilization. From the pollution by factories to the increased methane produced by cows and other livestock man has cultivated in larger and larger numbers to sustain human beings. This process alone would be enough to skew the numbers that the authors data produced rendering the usual trend variances somewhat meaningless. Somewhat in that the report itself certainly has raised this very useful question of economic and climate change that should not be altogether ignored.

The authors also fail to adequately address particular instances of economic problems and certain countries. Quite often political climates more than temperature variations have more to do with economic difficulties. For instance, in a specific example we have Africa whose economic development has been stymied by many factors:

Not only is Africa the poorest region in the world, but it was also the only major developing region with negative growth in income per capita during 1980-2000. Some African countries grew during the 1990s, but for the most part this growth recovered ground lost during the 1980s.

While the date range for this sample is admittedly too small for the authors to take into account, these types of variance certainly are additive over centuries as well and need careful consideration before completely ruling them out.

This article certainly has a massive amount of data to reconstruct and to correlate into a coherent whole. The task itself was Herculean and although derived from other's original research it is nonetheless compelling and substantive. However, the authors main weakness is the data itself, in that it can be presented in a number of ways to draw differing conclusions and does not take into account more powerful variables, such as political and governmental issues as well as the population growth. These may at first seem minor in comparison to the centuries but certainly have a cumulative effect upon any nations economic growth.