Page 65 - Materials Chemistry, Second Edition

48 A. Moltesen and A. Bjørn

5.4 Sustainability and LCA

If sustainability entails that the environment has to be conserved, the question is
How can we conserve the environment? What are the overall drivers that lead to
environmental deterioration?
These questions were first addressed in Holdren and Ehrlich (1974), whose work
in a modified form lead to the formulation of the so-called IPAT equation, or

I ¼ P A T ð5:1Þ

where (I) is the environmental impact, (P) is the population, (A) is the per capita
affluence and (T) is the technology factor.
The formula expresses that the overall impact on the environment is controlled
by the number of people on the planet, their affluence, expressed in material
affluence per person, and technology’s environmental intensity, expressed in
environmental impact per material affluence.
Figure 5.2 shows the global development in population and various indicators of
affluence, such as GDP, transportation and paper production, along with indicators
of environmental pressures and impacts from 1750 to 2010. Figure 5.2a shows that
while the world population has almost tripled from 1950 to 2010, all the indicators
of affluence have increased at higher rates, meaning that the per capita affluence
(“A” in the IPAT equation) has increased in the period (note that this increase has
been unequal—income differences between and within countries have increased in
the period). Figure 5.2b shows that the combined effect of an increasing population
and increasing per capita affluence (“P” and “A” in the IPAT equation) has led to
increases in environmental pressure and impacts (“I” in the IPAT equation). This
means that technological improvements in environmental impact per material
affluence (“T” in the IPAT equation) have been insufficient for maintaining envi-
ronmental pressures and impacts at a status quo, let alone for decreasing them.
With the historical development in mind, the IPAT equation shows us that we, in
theory, have three overall knots and handles to manipulate to ensure that loads on
the environment do not exceed carrying capacities. Two of these three parameters,
the number of people and their affluence, have been difficult to handle. In relation to
the number of people, this can either be regulated by increasing mortality or
reducing fertility, and in most parts of the world issues like these are not on the
political agenda. In some parts of the world, for example in the EU, Russia and
Japan, it is even seen as a political aim to increase fertility. However, despite this,
projections show that the world population may stabilize around 10 billion in 2050.
With regards to the affluence, we have already established above that to increase
the intra-generational equity, there is a need for increasing the affluence of the ones
mostly in need. Reducing the overall affluence while increasing the affluence of the
poorest inevitably calls for a decrease in the affluence of the richest part of the world
population which is a difficult program for a political party striving for (re-)election