Nine components are synthesized in the HPI to produce a composite snapshot at a country level across all nations. Two indicators that express potentiality and one indicator that expresses burden are integrated into a sub-index for each sphere using normalization and integration procedures. All data sources for calculating HPI are summarized in table 1. In order to ensure normalization, two processes are carried out: (1) the distribution of the target parent population is converted into a normal distribution that uses 0.5 to represent the mean value, and (2) if any scores fall under 0 or above 1, these scores are replaced with 0 and 1, respectively. The first process is used to calculate the deviation of each sample population to the entire targeted parent population, and the second process is aimed at reducing the influence that any outliers in the population can exert on the evaluation of other samples. Through this normalization, the three indicators in each sphere are converted into scores that fall between 0 and 1. Although the analysis for constructing HPI employs 115 countries in the world as the parent population, due to restrictions to accessible data, the spatial bias introduced by defective data is relatively small as illustrated in the maps found in this site.
Scores calculated through normalization reveal how the components of HPI are ubiquitously distributed across space when viewed from a global perspective. The three indicators for each sphere are integrated into the sub-index of each sphere through the following equation:`"Sub-Index" = (("Potentiality indicator 1") + ("Potentiality indicator 2") + (1 - "Burden indicator"))/3 `
The sub-index of each sphere refers to the simple average of three normalized characteristic indicators and treats all three equally without being weighted. In effect, HPI is an index that synthesizes three sub-indices; the geosphere sub-index, the biosphere sub-index, and a human society sub-index. After normalization, the index is then calculated through the following equation:`"Humanosphere Potentiality Index" = (("Geosphere Index") + ("Biosphere Index") + ("Human Society Index"))/3 `
The humanosphere potentiality index offers a synthesis of the three spheres. The index that indicates the average of all three sub-indices is the HPI. In this index, the scores for the tropical zones of Southeast Asia and Latin America are high, as are the scores for Central Africa. Table 2 shows that in the countries with the highest figures of the HPI, the human society sub-index is above average in most of the countries. This is in addition to the fact that the sub-indices of geosphere and biosphere are also generally high.
The geosphere sub-index is high in areas with an abundance of solar energy and available water, which are related to global heat and water circulation, while scores are lower in areas with high levels of burden caused by human society in terms of GHG emissions. Countries with high scores are concentrated in the tropical zone. In spite of their geographical locations, the scores in the Sahel area, the southern part of the African continent, the Middle East, and Mexico all demonstrate relatively low scores primarily due to dry climates. In particular, the low figure found in the oil-producing states is led by high GHG emissions. The dry climate found in these areas is largely the result of the subtropical high-pressure belt that is generated by Hadley circulation. Temperate countries generally show low figures. However, those countries that have unique characteristics in their geographical conditions or energy consumption patterns tend to present a relatively higher figure, as is the case with Japan due to its abundance of water resources, and Afghanistan with its low levels of GHG emissions.
The biosphere sub-index presents a comparison between a world map of the geosphere and one illustrating the biosphere sub-index. In general, biosphere sub-indices for the tropical zone are high. Four indicators, solar energy, air and water circulation, biomass, and biodiversity are strongly correlated and significant at the 1% in the tropics. On the other hand, there is a strong correlation between solar energy and biodiversity and also between air and water circulation and biomass, but none between air and water circulation and biodiversity or between solar energy and biomass in temperate zones. In both the temperate and tropical zones, we can find an observable tendency that reveals that biological resource use is high in places with strong air and water circulation and an abundance of biomass. However, in the temperate zone, an inverse correlation between the strength of solar energy and biological resource use can be seen. The biosphere sub-index is slightly elevated in temperate countries such as Australia, the United States, China, South Africa, Japan, and Argentina.
The human society sub-index clearly shows that there is a high score in Southeast Asia and in the Great Arid Zone, which stretches from Morocco to Mongolia, and a high score in temperate countries including those found on the North American continent and the temperate countries of South America. The elevated score of the tropical zone is not as evident here as in the sub-indices of the geosphere and biosphere.
What reasons explain why the human society composite index is relatively low in certain parts of the tropical zone? One factor that causes patchy patterns in Southeast Asia, South Asia, West Asia, and North Africa is variations in care relations. In particular, in West Asia, North Africa, and South Asia, there are many large households but these regions also include countries where significant FMR imbalances exist within the population. When the influences of FMR imbalances are set aside, the sub-indices for South Asian countries, where the average number of people per household and the population density are both high, present the highest scores. However, when the human society sub-index is employed –as it addresses adjusted care relations that include FMR imbalance, the scores of these countries become low. Alternatively, the low score of the human society sub-index in tropical Africa is led by a number of facts; population is lower than in comparison with Asia, the size of the household is smaller than Asia, and unexpected deaths from infection and conflicts are much more frequent. In particular, the low score for Sub-Saharan Africa is strongly influenced by the number of deaths from infections including tuberculosis, HIV/AIDS, and malaria. In South America, the low score in some countries such as Colombia and Venezuela is notable, but this is the result of high rates of death from murder and conflict, in addition to a low population. The low scores in temperate industrial countries, particularly in Northern Europe and Russia, are influenced by high rates of suicide in addition to a low population and the small size of households.