The environmentalist view of the energy intensity is based on the legacy of the I = PAT equation in which environmental Impact equals Population, multiplied by Affluence, and further multiplied by Technology (Earth Report 2000: Revisiting the True State of the Planet. 1999). The further desegregation of this formula implies that energy intensity can be looked upon as an integrative variable describing the impact of both technology and affluence. Bruce et al.
(1996) argue that intensity is inversely related to efficiency. Improving efficiency reduces the amount of energy required to provide a given output, i. e. an output of the same quality and quantity. In real life, though, the precise nature of the output is unknown, hence intensity is a proxy for efficiency.
The Kaya Identity is an expression that is introduced by Bruce et al. (1996) to describe the relationship among the factors that influence trends in energy-related carbon emissions: C = (C / E) (E / GDP) (GDP / POP) POP. The formula links total energy-related carbon emissions (C) to energy (E), the level of economic activity as measured by Gross Domestic Product (GDP), and population size (POP). The first two components on the right-hand side represent the carbon intensity of energy supply (C/E) and the energy intensity of economic activity (E/GDP). Economic growth is viewed from the perspective of changes in output per capita (GDP/POP).
At any point in time, the level of energy-related carbon emissions can be seen as the product of the four Kaya Identity components - energy intensity, carbon intensity, output per capita, and population size. In fact, growth in energy intensity in industrialized countries has historically lagged behind economic growth, whereas the two are more closely correlated in developing countries. As a country's energy intensity changes, so does the influence of a given level of economic activity on carbon emissions. Increase energy use and economic growth generally occur together, although the degree to which they are linked varies across regions and stages of economic development (Mies 2000). In CCEE, the energy situation is characterized - when compared with CWE - by very high energy and electricity intensities. According to rge-Vor satz and Szeszler (1999), this situation can be attributed to three main elements: a) The largest part of the GDP is due to industrial production, with an emphasis on heavy industries (iron and steel, chemicals, machinery) which are big energy consumers.
b) The very low level of energy efficiency of end-use devices, equipment and appliances is aggravated by the lack of maintenance and the obsolescence of the equipment. c) The economic crisis which the CCEE countries have been enduring since 1989-1990: a deep slow down in industrial production, a lack of investment in the energy sector, the non-payment of energy by the consumers, in particular in the energy sector itself. Alongside with the energy efficiency gap between CCEE and CWE, the life expectancy gap exists. Hertz man et al.
(1996) show diverging trends in life expectancy becoming evident in the mid-1970 s, and the gap continued to widen in the 1980 s for all major causes of death, particularly cardiovascular diseases. The situation is worse in the Newly Independent States than in the CCEE, and worst in the Central Asian countries (Nanda et al. 1993). There is no single reason for the health gap - Wahlberg (1998) points out - but contributory factors include the increasing prevalence of major risk factors in the quality of environment.