The human ecology of climate change - Climate Change: Biological and Human Aspects - page 365

but occasionally it is considered in this way: one example would be the concept of
a community's, or a nation's, ecological footprint. More often than not, impact is
considered as relating to a development project, be it an airport or the construction
of a road, when an environmental impact assessment is carried out.
Policy-makers rarely consider environmental impact in human population terms.
Instead, much of their focus is on either the affluence or technological dimensions; that
the policy in question will have to generate this much wealth for that much cost, incid-
entally generating so much pollution. Attempts to curb population through lowering
fecundity 1 are rarely considered as a means to curb impact or frame economic and
sustainability policies. There are exceptions, the most notorious being China in the
late 20th century; 'notorious' because China's draconian measures greatly infringed
individual freedom and distorted its population's gender balance. However, in the
main, up to the early 21st century addressing population issues has been low on
policy agendas.
More recently there has been some interest in population, P in the above equation;
population concerns have slowly begun to come to the fore. Politicians in developed
nations perceive that current population demographic changes (the changes in a pop-
ulation's composition, such as by age) mean that there will not be enough younger
people to care for the increasing number of elderly (and especially partially infirm
elderly, for we are living longer more in an unhealthy state). The early 21st century has
seen a number of developed nations, such as the USA, UK, Italy and Australia, actively
introduce policies to address this problem, be it through immigration or fiscal encour-
agements to increase fecundity for couples wanting children. Consequently, following
the Ehrlich-Holdren equation, such policy trends are likely to increase environmental
impact rather than reduce them. Indeed, because the citizens of developed nations are
more affluent the environmental impact arising from each one is greater than in their
less-developed counterparts, so actively encouraging a growing developed nation's
population will often (but not always) tend to increase that population's environmental
impact. However, some academics do present detailed arguments as to why popula-
tion growth might be seen in a positive light (Simon, 1996) and, as we shall see, the
addition of an extra person to a population can result in either an improvement or a
decline in the wealth-to-impact ratio.
As per the Ehrlich-Holdren impact equation carbon dioxide emissions do broadly
(but again, not always) relate to affluence in terms of gross domestic product (GDP; the
sum total of that population's earnings) and GDP per capita. In the late 20th century,
affluent North America (Canada and USA), with approximately 2% of the global
population, was responsible for about 25% of greenhouse gas emissions. Conversely,
less wealthy China, with some 20% of the Earth's population, then generated just 12%
of global emissions. The carbon emissions per capita from energy use for selected
countries in 2002 and 2009 are depicted in Figure 7.1. From this it can be seen that

1

Until recently many demographers used fertility to mean both the actual level of human reproduction
and the potential for human reproduction, even though these concepts are quite different. More exact
terminology is required (especially when communicating across disciplines) and increasingly the eco-
logical term fecundity is used to relate to the amount of offspring a human couple actually have, while
fertility is used to reflect the potential to have offspring. This is how these terms are used in this topic.